abstract. On the final day of Justice Breyer’s tenure on the U.S. Supreme Court, the Court formally recognized the major questions doctrine, which requires an agency to point to “clear congressional authorization” before it exercises a novel power with economic and political significance. Though its origins are disputed, our account traces the doctrine to MCI Telecommunications Corp. v. AT&T—a decision announced just months before Breyer joined the Court—and from there to an article Breyer penned while a judge on the U.S. Court of Appeals for the First Circuit. The doctrine therefore provides a vantage point from which to survey Breyer’s administrative-law jurisprudence in panorama. That is this Essay’s aim.

We begin by examining the major questions doctrine, the details of which remain hazy, in large part because the Court is of many minds about what Congress does when it gives discretion to agencies. Justice Breyer had one answer, to which the Essay turns next: Congress legislates in broad strokes but leaves it to agency experts to fill in the details. Courts police these experts at the boundaries. Breyer’s answer led him to follow the logic of the major questions doctrine in some cases but not others. The key, for him, was flexibility. Over the course of his tenure, Breyer’s case-by-case approach guided the Court to treat questions of deference with nuance. But an increased appreciation for the degree of policy-making authority agencies wield has more recently led the Court to utilize the major questions doctrine in a manner at odds with Breyer’s judicial philosophy. The Essay traces this evolution and concludes by predicting an uncertain future for a doctrine with such unstable foundations.

Introduction

As Justice Stephen Breyer retires, he leaves behind a body of administrative law that owes much of its shape to his work both on and off the bench. He treated Congress’s delegation of authority to the modern administrative state as a pragmatic and flexible solution to the challenges of governing an increasingly complex society. He displayed sympathy and patience toward Congress and administrative agencies as they confronted these challenges. Throughout his more than forty-year judicial career, he diligently took up what he believed to be the courts’ responsibility: to endeavor to understand Congress’s intent with respect to a given regulatory scheme and to resolve disputes with an eye toward achieving Congress’s purpose. His sensibilities reflect his broader commitment to “active liberty”—giving democratic majorities room to address societal problems.1 Many aspects of today’s administrative law bear the mark of these sensibilities.

On the final day of Justice Breyer’s final term, the Supreme Court issued an important administrative-law decision: West Virginia v. Environmental Protection Agency (EPA).2 That decision invoked for the first time the term that lower courts and commentators had been using to identify a “body of law that ha[d] developed over” the course of Breyer’s tenure: the “major questions doctrine.”3 This Essay considers how the major questions doctrine fits into Breyer’s administrative-law legacy and how the doctrine may evolve after his retirement.

The major questions doctrine instructs courts to presume that Congress does not delegate policy decisions of great economic and political magnitude to agencies. It has come to be seen as a tool for paring back agencies’ authority, so one would expect Justice Breyer—a proponent of the modern administrative state—to oppose it. And indeed, he has often, but not always, found himself on the other side of Supreme Court opinions that have wielded the doctrine. Most famously, he dissented from the Court’s decision in Food & Drug Administration v. Brown & Williamson Tobacco Corp., which contains the seminal statement of the major questions principle.4

And yet, the major questions doctrine takes its name from Breyer’s own writing. When he was a judge on the U.S. Court of Appeals for the First Circuit, he wrote an article in which he advocated softening Chevron’s command that courts defer to agencies.5 Then-Judge Breyer argued that, before deferring to an agency’s statutory interpretation, courts should “ask whether the legal question is an important one.”6 As he explained, “Congress is more likely to have focused upon, and answered, major questions, while leaving interstitial matters to answer themselves in the course of the statute’s daily administration.”7 The Supreme Court agreed and cited his article in Brown & Williamson to support its decision not to defer to the Food and Drug Administration’s (FDA’s) judgment that the Food, Drug & Cosmetics Act allowed it to regulate tobacco.8

Part I of this Essay provides an overview of the major questions doctrine. The term describes not a unitary doctrine, but rather a collection of related principles concerning congressional intent and the separation of powers. Part II describes Justice Breyer’s administrative-law jurisprudence. Like his approach to other areas of law, Breyer’s administrative-law jurisprudence is pragmatic and optimistic. He shuns rules in favor of multifactor analyses designed to exploit the institutional competencies of the different actors that formulate, enforce, and interpret regulatory policy. His Chevron jurisprudence reflects some of the principles that make up the major questions doctrine, while rejecting others. Part III concludes by tracing the trajectory of the major questions doctrine and identifying the forces that will influence its future direction. The doctrine is on a path to become a clear-statement rule that requires agencies to cite unambiguous statutory support for regulatory initiatives with great economic and political significance. But, as with any judge-made rule, the doctrine could easily change direction.

I. the major questions doctrine

In 1994, the Supreme Court handed down its decision in MCI Telecommunications Corp. v. AT&T.9 That case presented the question whether the Federal Communication Commission’s (FCC’s) authority to “modify any requirement” imposed by the Communications Act included the ability to relieve long-distance carriers of the obligation to file their rates. In an opinion by Justice Scalia, the Court held that the Commission enjoyed no such authority. The Court reasoned, “It is highly unlikely that Congress would leave the determination of whether an industry will be entirely, or even substantially, rate-regulated to agency discretion—and even more unlikely that it would achieve that through such a subtle device as permission to ‘modify’ rate-filing requirements.”10

These words marked a departure from the deference courts usually give to agencies’ interpretations of the statutes they administer. The Chevron doctrine instructs courts to treat statutory silence or ambiguity as an implicit delegation of authority from Congress to the agency.11 The doctrine “presum[es] that Congress, when it [has] left ambiguity in a statute meant for implementation by an agency, understood that the ambiguity would be resolved, first and foremost, by the agency, and desired the agency (rather than the courts) to possess whatever degree of discretion the ambiguity allows.”12 Courts must therefore respect any “permissible” or “reasonable” construction of ambiguity or silence in a statute when that statute is administered by the construing agency.13

The Supreme Court “most often describe[s] Congress’ supposed choice to leave matters to agency discretion as an allocation of interpretive authority.”14 But the Court also “sometimes treat[s] [an agency’s] discretion as though it were a form of legislative power.”15 Chevron itself acknowledges that agencies are not selecting the soundest textual interpretation of the statute but are instead “formulat[ing] policy.”16 Accordingly, agencies’ decisions have the force of law even if “‘Congress did not actually have an intent’ as to a particular result.”17

MCI Telecommunications laid the groundwork for what has become known as the major questions doctrine. The doctrine, in contrast to the Chevron doctrine, commands courts to cast a jaundiced eye on an agency’s claim that Congress delegated to it a decision of significant “economic and political magnitude.”18 Under either conception of Chevron described above, the agency is performing functions conventionally performed by the judiciary or the legislature: saying what the law is or what it shall be.19 Reversing that delegation by means of the major questions doctrine, then, restores power to the courts, Congress, or state legislatures.20 A court that cites the major questions doctrine to substitute its statutory interpretation for that of an agency is reclaiming authority Chevron would otherwise vest in the agency. A court that cites the major questions doctrine to deny the agency policy-making authority21 reserves the policy choice for the federal or state legislatures.

The justifications offered for the major questions doctrine will depend on how it operates in a given case. For example, each branch’s institutional competencies point in different directions, depending on what function or functions they are passing back and forth.22 If one is concerned about political accountability, then restoring power to Congress promotes that institutional value, while restoring power to the courts does not.23 If one is concerned about expertise, then one might favor restoring interpretive authority to the courts, but not overriding policy judgments by the agencies. And if one believes that an agency is selecting from a range of policy options instead of from a range of interpretations of fixed statutory language, one might place greater emphasis on flexibility.24

Uncertainty about the nature of the function the Chevron doctrine allows agencies to perform (interpretation or policy making) perhaps arises from the fact that it is a judge-made doctrine with a doubtful rationale.25 That foundational uncertainty, in turn, may have prevented the bundle of principles associated with the major questions doctrine from coalescing into a single, coherent rule for the past thirty-odd years. Although the Court decided MCI Telecommunications in 1994, it did not name the doctrine that decision launched until this past term, in West Virginia v. EPA. The still-sparse caselaw leaves unanswered at least three key questions about the major questions doctrine.

First, what makes a question “major”? The Supreme Court has answered this question in both absolute and relative terms. The first possibility is that courts should measure a question’s significance by some absolute standard external to the statute: perhaps the court’s own assessment of the question’s importance or the degree of attention Congress has given to the subject.26 Brown & Williamson relies on these measures, emphasizing tobacco’s cultural and economic significance in American life, as well as the number of tobacco-specific legislative initiatives Congress had considered in the preceding decades.27 Justice Gorsuch also advocates an absolute standard in his West Virginia concurrence, where he provides a nonexhaustive list of political, economic, and structural considerations.28

Another possibility is that courts should measure a question’s relative significance by its place in the statutory or regulatory scheme—that is, by the size of the “eyebrow-raise” the agency’s answer provokes.29 Does this question more closely resemble questions that Congress resolved explicitly, or the sorts of interstitial questions that Congress left to the agency? How much does the answer to the question at issue change the shape of the broader legislative initiative? Congress “does not alter the fundamental details of a regulatory scheme in vague terms or ancillary provisions—it does not, one might say, hide elephants in mouseholes.”30 To decide whether a question qualifies as an “elephant,” one must know the size of the “mousehole.”31 King v. Burwell exemplifies this approach: the Court’s determination that the question whether health insurance policies qualify for tax credits was a major one turned on the question’s centrality to the statutory scheme.32 So, too, the West Virginia dissent uses a relative measure when it accounts for the major questions line of cases as those in which “the agency had strayed out of its lane, to an area where it had neither expertise nor experience.”33

Of course, courts often invoke both absolute and relative measures of significance when applying the major questions doctrine, and it is possible that either form of significance should trigger a less deferential form of judicial review.34 But it is not clear that the justification for independent review remains the same whether one is talking about a vast expansion of agency power (as in Brown & Williamson) or a fundamental alteration in the regulatory scheme (as in King). Indeed, some have described the rule that neither courts nor agencies should interpret indefinite statutory provisions to fundamentally alter the statutory scheme as a doctrine that is distinct from, though related to, the major questions doctrine.35 Similarly, the Court’s “major questions” analysis sometimes sidles up to other, substantive canons that have their own independent rationales.36

How one measures significance relates to the more fundamental question discussed above: whether Chevron allocates interpretive or policy-making authority. An impulse to preserve legislative control over decisions that will have a substantial impact on Americans’ lives may make courts more reluctant to give agencies the final word on policy decisions that are “major” in an absolute sense. By contrast, a desire to preserve the judicial prerogative to “say what the law is” may lead courts to refuse to give agencies the final word on the interpretation of statutory provisions that are “major” in the relative sense.

Second, how does the doctrine interact with Chevron? In the absence of the major questions doctrine, courts usually formulate Chevron as a two-step test.37 At Step One, a court asks whether the statute is ambiguous. If it is not, then the court applies the statute’s unambiguous meaning.38 If the statute is ambiguous, then the court proceeds to Step Two, where it asks whether the agency’s interpretation is reasonable.39 Some commentators have also argued that there is an unspoken “Step Zero”—a threshold determination of whether the Chevron framework applies to begin with.40 Where does the major questions doctrine fit into this analysis?41

In some cases, courts treat the major questions doctrine as one that reverses Chevron’s presumption about who gets to interpret the statute.42 In these cases, the doctrine operates at Chevron Step Zero because it redirects the court away from the Chevron framework.43 The court is under no obligation to defer to the agency’s interpretation of the statute, even if the statute is ambiguous, and even if the agency’s interpretation is reasonable.44 The court may, however, adopt the agency’s preferred construction of its own accord.45 So understood, the major questions doctrine reclaims interpretive power for the courts but does not necessarily return policy-making authority to Congress.

In other cases, courts rely on the doctrine to inform their answer to the underlying statutory-interpretation question. In these cases, the major questions doctrine may be an input at Step One or Step Two46 or operate entirely apart from the Chevron framework.47 The court reads the statute not to give the agency a substantive regulatory power because the statute is at best ambiguous as to whether the agency possesses that power, and the doctrine assumes that Congress does not delegate such significant decisions ambiguously.48 So understood, the major questions doctrine guards against excessive delegations of policy-making authority from Congress to administrative agencies.49

The distinction between these two approaches may explain why the Court resolved one of the most significant regulatory questions to come before it this century without relying on or even confronting the major questions doctrine. In Massachusetts v. EPA, the Court considered whether the Clean Air Act’s definition of “air pollutant” includes greenhouse gases believed to contribute to global warming.50 EPA argued,51 and the Court later held in another case,52 that this was a “major question” because defining “air pollutant” to include greenhouse gases would massively expand EPA’s authority and have a significant impact on the American economy. In Massachusetts, however, neither the majority nor the dissent addressed the major questions doctrine.53 The majority simply held that the plain meaning of the term “air pollutant” encompassed greenhouse gases,54 a conclusion that is consistent with an understanding of the doctrine as a Chevron Step-Zero rule. Because the Court found the statute to be unambiguous, it had no cause to determine whether the Chevron framework applied at all.55 By contrast, Justice Scalia’s dissenting opinion is more consistent with treating the major questions doctrine as a substantive input in statutory interpretation. EPA had disclaimed the power to regulate greenhouse gases, so the dissent could rely on the argument that EPA’s interpretation was at least a reasonable interpretation entitled to deference without using the major questions doctrine to establish that it was the only reasonable interpretation.56

Finally, does the doctrine’s presumption reflect the way Congress does act or the way Congress should act? The Chevron doctrine purports to describe congressional intent to delegate a decision to an agency. The major questions doctrine began as a refinement of Chevron’s approximation of congressional intent: it assumed that Congress is less likely to delegate consequential decisions to agencies.57

The major questions doctrine has, however, taken on a normative cast as an expression of the nondelegation doctrine. By some accounts, then, the major questions doctrine presumes that Congress does not vest significant policy-making authority in agencies because Congress should not do so.58 The Constitution vests legislative power in Congress,59 and—in theory—Congress may not delegate that power to administrative agencies.60 Courts have long believed that their ability to enforce the nondelegation doctrine is limited because “[a] certain degree of discretion, and thus of lawmaking, inheres in most executive . . . action,” and it has proven difficult to craft a judicially administrable rule to distinguish permissible executive policy making from genuine exercises of legislative power.61 The major questions doctrine is a way to narrow the field in which the nondelegation doctrine remains underenforced because it, in effect, requires Congress to speak clearly if it wishes to delegate decisions of great political or economic significance to an administrative agency.62 Under this view, it would not matter that Congress intended to delegate the authority in question if Congress did not clear this judicially erected hurdle by expressing its intent clearly.

In theory, the divide between the descriptive and normative views is not as large as it might seem. Courts have long treated congressional intent as a “legal fiction” drawn less from empirical observations about the mental state of the legislators who enacted the law, and more from a series of assumptions about how a “reasonable legislator” would have acted.63 A reasonable legislator would act the way a reasonable legislator should act, or so the theory goes.64 That said, the distinction between the two attitudes toward major questions has proven consequential, as we will discuss below.

This final puzzle relates closely to the first two. Where the question is merely “major” within the statutory scheme, the doctrine may operate more as an assessment of congressional intent. Where the question is “major” in an absolute sense, however, a court may be more inclined to resort to the nondelegation principle to explain its lack of deference. Moreover, someone looking to cut back on delegations of legislative power may well favor the canon variant of the doctrine—which denies the agency policy-making authority in the absence of an explicit delegation—over the Chevron-exception variant—which merely denies the agency interpretive power.

* * *

The Court published its decision in MCI Telecommunications one month after President Clinton announced that he was nominating then-Judge Breyer to fill Justice Blackmun’s seat.65 The Court published its decision in West Virginia two hours before Justice Breyer’s retirement took effect.66 The foregoing puzzles reveal that the doctrine born and christened at the edges of Breyer’s term is not (or at least, not yet) a unitary one, but rather a collection of related principles that operate to reduce agencies’ powers—whether interpretive or regulatory—over questions that are by some measure significant. One would expect someone with Breyer’s friendly attitude toward the administrative state to disfavor such a doctrine. The reality is more complicated.

II. justice breyer and the major questions doctrine

When Justice Breyer took his oath as an Associate Justice of the U.S. Supreme Court, he had already dedicated decades of his career to problems of administrative law and regulatory policy. As a professor at Harvard Law School, he had specialized in administrative law.67 As special and then chief counsel to the Senate Judiciary Committee, he had worked on a number of regulatory projects, including the Airline Deregulation Act.68 And as a judge on the First Circuit, he had not only decided appeals involving administrative law, but synthesized his ideas in books and articles.69

Justice Breyer’s writings on the administrative state reflect his faith in agencies’ will and capacity to regulate for the public good.70 In his view, courts should decide cases in ways that help agencies further their public-good mission. As a judge, he approached that task pragmatically, using congressional intent as his lodestar and making case-by-case adjustments to account for a range of practical considerations and real-world observations. In ascertaining what Congress intended (or should have intended), he considered the characteristics and competencies of the branches of government involved in a given statutory scheme.71 Subject-matter expertise, flexibility, and accountability were chief among the institutional characteristics that informed Breyer’s understanding of congressional intent.72

Justice Breyer famously deployed flexible standards to resolve cases, meaning that his decisions depended heavily on the facts and practical implications of a given dispute.73 He rejected any rule that limited judges’ ability to dispose of a case in a way that “ma[d]e law work for people.”74 These features of Breyer’s jurisprudence combined to script a modest role for courts reviewing agency action: according to Breyer, courts should leave Congress and agencies free to allocate authority, structure decision-making, and formulate policy in a way that best promotes the public good, while courts police the boundaries of rational action through fact-intensive, case-by-case correction.

Justice Breyer arrived on the Court as one of the leading critics of the Chevron doctrine, which he found too rigid to accommodate the case-by-case approach to judicial review that he favored. Breyer believed that “there are too many different types of circumstances . . . to allow ‘proper’ judicial attitudes about questions of law to be reduced to any single simple verbal formula.”75 Moreover, he “consider[ed] that broadly requiring deference in situations of statutory silence or ambiguity is to risk mandating an overly restrictive judicial approach in the very area in which courts are most qualified.”76 His attitude was such that, when he first took the bench, the “prediction that Breyer’s influence may well increase the proportion of cases in which the Court upholds an agency’s construction of its authorizing statute” was labeled “counter-intuitive.”77

To soften Chevron’s rigidity, Justice Breyer believed that courts should “work out a unified set of principles . . . that [would] allow a court to formulate a ‘proper’ judicial attitude in individual cases.”78 He favored an approach to deference that would account for “the comparative institutional competence of a court or agency to answer the specific question, the information available to the courts and agency to decide the question on review, and the need for flexibility to accommodate policy requirements.”79 Among other things, courts should “ask whether the legal question is an important one”80because “Congress is more likely to have focused upon, and answered, major questions.”81 As already noted, the major questions doctrine takes its name from this formulation.82 Breyer has nevertheless regularly found himself on the other side of opinions invoking the major questions doctrine to reject agency constructions of statutes.83 Why is this?

The simple answer is that the major questions doctrine—in Justice Breyer’s eyes—suffers from the very defect that afflicts the Chevron doctrine: rigidity. Just as he disfavored treating Chevron as a switch that flips deference on whenever a statute is ambiguous, so too did he disfavor treating the major questions doctrine as a switch that flips it off whenever the legal question is significant. In his view, ambiguity and significance are merely factors to be placed on one side of the scale or the other. In some cases, other factors—like the need for flexibility—weigh more heavily in favor of deference than the significance of the question weighs against it. And sometimes, the significance of the question favors deference when it is combined with the other factors, especially institutional competence.84 Breyer’s answers to the questions we posed above further illuminate his approach to the major questions doctrine.

First, what makes a question major? Justice Breyer’s statement of his major questions principle suggests that he measured the significance of a question by its relative position in the statutory or regulatory scheme, as opposed to by an absolute, external standard.85 He distinguished major questions from “interstitial” ones: those that occupy the gaps in a statute’s design.86 By contrast, as discussed further below, Breyer was more likely to defer on questions that were “major” in the absolute sense.

Justice Breyer’s reliance on a relative measure of significance makes sense when one considers his position on the respective competencies of courts and agencies. Courts are more competent at interpreting legal texts, and thus at answering a question whose resolution has a significant impact on the meaning of the statute.87 By contrast, agencies are more competent at formulating policy, and thus at answering a question whose resolution has a significant impact on matters of economic and political concern.88 Even so, Breyer still deferred on some questions that were “major” in the relative sense. According to Breyer, a question could be “interstitial” yet “important to the administration of the statute” and trigger deference in part because its administrative significance called for the agency’s expertise.89

Second, how does the doctrine interact with Chevron? Although he proposed it as a threshold consideration, Justice Breyer’s major questions principle does not convincingly argue for dispensing with the Chevron framework altogether once a court has determined that an interpretive question is a major one. Recall, he reasoned that “Congress is more likely to have focused upon and answered, major questions.”90 “If Congress has, in fact, focused upon, and answered, major questions, agencies” and courts “must accept those answers under Chevron Step One.”91 There is no need to throw out the Chevron framework to effect congressional intent; the court simply needs to implement Congress’s answer, as it always does at Step One when Congress has answered the question. Breyer has nevertheless joined at least one opinion holding that the major questions doctrine creates an exception to Chevron.92 Under the logic of that opinion, the doctrine allows courts to decide de novo whether an ambiguous statute authorizes administrative action—a scenario to which Breyer’s major questions rationale does not appear to extend.

In any event, Justice Breyer has, with one notable exception,93 dissented from opinions that use the major questions doctrine as a canon of construction to limit agencies’ substantive regulatory powers.94 He disfavored any canon that made it more difficult for Congress to empower agencies to act on matters of absolute economic and political significance. In fact, Breyer was inclined to find broad substantive delegations precisely where the stakes were high, on the ground that high-stakes problems demand flexibility. Thus, in Brown & Williamson, he argued that the Court “should interpret the [Food, Drug, and Cosmetic Act] in light of Congress’ overall desire to protect health.”95 According to Breyer, “[t]hat purpose require[d] a flexible interpretation”—namely, one that allowed FDA to rely on ever-advancing scientific knowledge to select which substances to regulate and how.96

Justice Breyer’s conviction that Congress should—and therefore does—give agencies flexibility to meet the unexpected was so firm that, in many cases in which he opposed the major questions doctrine, he did so not on Chevron grounds, but instead on the ground that Congress unambiguously delegated regulatory authority on matters of immense economic and political significance.97 In Massachusetts v. EPA,98 for example, he joined a majority that declined the agency’s invitation to apply the major questions doctrine99 because he believed that the statute unambiguously required EPA to regulate greenhouse-gas emissions if it believed they were a threat to public health. Despite the widely acknowledged significance of the questions at issue—whether and how to regulate greenhouse gases—the majority opinion in Massachusetts v. EPA did not look to the Clean Air Act for a clear statement that EPA must regulate greenhouse gases; indeed, the Court acknowledged that “the Congresses that drafted [the statutory provision at issue] might not have appreciated the possibility that burning fossil fuels could lead to global warming.”100 The Court nevertheless discerned in the broad language of the act “an intentional effort to confer the flexibility necessary to forestall [the] obsolescence” that would befall the Clean Air Act if EPA could not respond to “changing circumstances and scientific developments.”101 The same, pragmatic rationale recurs in Breyer’s own opinions on major questions.102

Finally, does the doctrine’s presumption reflect the way Congress does act or the way Congress should act? Justice Breyer endorsed a major questions principle as a refinement of the “legal fiction” through which courts seek to give effect to Congress’s intent.103 In Breyer’s view, this presumption that Congress does not leave major questions to agencies may be rebutted by other indications—such as broad language—that Congress did intend to delegate a major decision to an agency. According to Breyer, “the ultimate question is whether Congress would have intended, and expected, courts to treat an agency’s rule, regulation, application of a statute, or other agency action as within, or outside, its delegation to the agency of ‘gap-filling’ authority.”104

By contrast, Justice Breyer was usually unmoved by the separation-of-powers principles that undergird the nondelegation variant of the major questions doctrine. For example, while opponents of delegation have argued that major questions of policy ought to be resolved by democratically elected members of Congress,105 Breyer has rejoined that major questions are the ones on which agency administrators are most likely to be held democratically accountable through the President.106 Breyer has also questioned whether courts employing the major questions doctrine truly return authority to Congress, arguing that they instead arrogate these choices to the least accountable branch: the judiciary.107

This is not to say that Justice Breyer’s version of the major questions doctrine is devoid of normative content. As noted, he treated Chevron as a legal fiction crafted by courts seeking to “imagine what a hypothetically ‘reasonable’ legislator would have wanted.”108 In Breyer’s view, that exercise required courts to “decide whether [delegation] ‘makes sense,’ in terms of the need for fair and efficient administration of that statute in light of its substantive purpose.”109 This, in turn, means “allocat[ing] the law-interpreting function between court and agency in a way likely to work best within any particular statutory scheme.”110 As the foregoing discussion shows, Breyer’s answer turned less on constitutional concerns and more on a judgment about an agency’s expertise and flexibility to respond to the problem Congress wished to solve.

In sum, Justice Breyer preferred a flexible approach to deference that would leave agencies free to make policy within their zones of expertise, with courts policing their choices on a fact-intensive, case-by-case basis. Breyer’s influence is evident in the major question doctrine’s evolution over the course of his tenure.111

III. the trajectory of the doctrine

The Supreme Court has often reviewed agencies’ answers to questions that would seem to qualify as major—whether in an absolute or relative sense—without ever invoking the major questions doctrine or explaining why it does not apply.112 Like a piece of yarn woven through a dramatic tapestry, the major questions doctrine makes occasional appearances in the fabric of the Chevron doctrine. But its place in the tableau has become more pronounced as Chevron’s fortunes have fallen.

A. Past, Present . . .

MCI notwithstanding, Chevron was still in its heyday when Justice Breyer arrived on the Court.113 Justice Scalia famously defended it as an imperfect but laudably administrable “estimation of modern congressional intent.”114 Scalia’s view remained “triumph[ant],” if contested, throughout the 1990s.115 One of Breyer’s first Chevron majority opinions applied the rule in the straightforward manner Scalia championed.116

But as already noted, Justice Breyer favored a more nuanced approach to deference.117 The “triumph” of Breyer’s case-by-case approach, including his major questions principle, came in the early 2000s as Chevron began to fall out of favor.118 Two terms after Brown & Williamson consolidated the major questions reasoning from MCI, Breyer wrote for a nearly unanimous Court in Barnhart v. Walton.119 Although the Barnhart opinion nominally invoked Chevron, it justified its deference to the agency’s interpretation not just based on statutory ambiguity, but based on a range of factors, many of which were foreign to conventional Chevron analysis.120 The concluding paragraph captures in a nutshell Breyer’s multifaceted approach to agency deference, invoking “the interstitial nature of the legal question, the related expertise of the Agency, the importance of the question to administration of the statute, the complexity of that administration, and the careful consideration the Agency has given the question over a long period of time.”121

Since Barnhart, the Court has become increasingly troubled by the delegation of legislative power to administrative agencies and increasingly wary of Chevron as one channel through which that delegation occurs.122 This suspicion has invigorated the nondelegation features of the major questions doctrine and left Justice Breyer defending the Chevron doctrine.

In 2014, the Supreme Court revisited the meaning of “air pollutant” in Utility Air Regulatory Group v. EPA.123 Recall that seven years before, in Massachusetts v. EPA, the Court had ruled that the Clean Air Act’s act-wide definition of “air pollutant” unambiguously encompassed greenhouse gases—without invoking the major questions doctrine.124 In Utility Air Regulatory Group, the Court relied on the major questions doctrine to hold that the term “air pollutant,” as used in two separate provisions of the same Act, excluded greenhouse gases.125 Justice Breyer dissented, but not on the grounds one might expect. Everyone—majority, dissent, and agency—agreed that applying the statute as written would lead to “untenable” results if “air pollutant” included greenhouse gases.126 And everyone also agreed that the agency enjoyed a degree of discretion to interpret the statute to avoid that absurdity.127 But the majority perceived more constraints on the agency’s discretion than did Breyer.128 Among the principles of statutory interpretation the majority used to constrain the agency’s authority were both the major questions doctrine129 and separation-of-powers concerns about the agency’s exercise of legislative power.130 But the Court still treated them as distinct considerations.

Dissenting in part, Justice Breyer advocated focusing on practicalities rather than on text and structure. In response to the separation-of-powers concerns articulated by the majority, Breyer observed that EPA should be given the “flexibility” to deploy its superior “technical expertise and administrative experience.”131 He also invoked his major questions principle, arguing that the precise content of “air pollutant” was an “interstitial” question of the sort “Congress typically leaves to the agencies.”132 Unlike the majority, he expressly connected his major questions principle to the normative (institutional) principles that underpinned it.133

Meanwhile, the Court’s retreat from Chevron continued. Justice Breyer, writing for the Court in 2016, invoked Chevron to defer to the Patent Office’s gap-filling regulation concerning inter partes review.134 The decision tells us little about the Court’s disposition toward Chevron, however, because—as Justice Thomas noted in his concurrence—it did “not rest on Chevron’s fiction that ambiguity in a statutory term is best construed as an implicit delegation of power to an administrative agency to determine the bounds of the law.”135 Rather, Congress had expressly authorized rulemaking to fill out the details of inter partes review.136 Since that decision, the Court has consistently declined to defer to agencies under Chevron.137

In 2018, the Court considered overturning Chevron138 but ultimately left the question for another day.139 Writing for two other Justices in dissent, Justice Breyer pleaded for Chevron’s life by describing it as a mere “rule of thumb, guiding courts in an effort to respect that leeway which Congress intended the agencies to have.”140 Arguing that the “rule of thumb” favored deference in the case before the Court, he again invoked his version of the major questions principle, observing that the statutory provision before the court “constitutes a minor procedural part of a larger administrative scheme.”141 Two terms later, Justices Breyer and Kagan alone advocated giving Chevron deference to an agency’s interpretation of a statutory provision whose meaning was hotly contested.142

With the COVID-19 pandemic have come decisions that have strengthened the connection between the major questions doctrine and the nondelegation doctrine.143 Most notable is the Court’s decision staying the Occupational Safety and Health Administration’s (OSHA’s) so-called vaccine mandate.144 This decision is significant because it was the first in which the Supreme Court expressly treated the major questions doctrine as a rule of statutory interpretation that stands independently from the Chevron framework.145 Citing (indirectly) Brown & Williamson instead of Chevron, the Court framed the question not as whether Congress had spoken directly to the issue before the Court, but instead as “whether the Act plainly authorizes the Secretary’s mandate.”146 In other words, the Court required the agency to point to a provision placing the policy choice in the agency’s hands, instead of requiring the challenger to point to a provision taking the choice away from the agency, as the Chevron doctrine arguably does. In a concurrence, Justice Gorsuch (joined by Justices Thomas and Alito) described this requirement of plain authorization as “closely related to . . . the nondelegation doctrine.”147 He then finalized the major question doctrine’s divorce from the Chevron doctrine by tracing the major questions doctrine, and its nondelegation ancestry, to a pre-Chevron decision.148

A central theme of the vaccine-mandate opinions is, “Who decides?”149 The COVID-19 pandemic has required our government to make difficult trade-offs between public health and individual liberty. The per curiam opinion in NFIB v. OSHA argued that “[i]n our system of government, [weighing tradeoffs] is the responsibility of those chosen by the people through democratic processes.”150 Justice Gorsuch agreed and asserted that the major questions doctrine was an important tool for restoring the decision to the proper decision maker: the doctrine is “designed to protect the separation of powers and ensure that any new laws governing the lives of Americans are subject to the robust democratic processes the Constitution demands.”151

Justice Breyer and his fellow dissenters saw the matter differently. In their view, OSHA had made the tradeoffs the people’s representatives charged it with making, and, by staying the mandate, the Court “displace[d]” OSHA’s democratically endowed judgment.152 One could view this departure as a simple disagreement over whether Congress gave OSHA the authority it claimed. But that disagreement traces back farther, to the opinions’ respective starting points: the dissent flipped the majority’s presumption, asking not whether Congress had clearly conferred this authority, but instead whether Congress had clearly denied it.153 Although Breyer and his fellow dissenters did not rely on Chevron, their reasoning allocated the burden in much the same way that Chevron does.154 For the dissenters, the political and economic significance of the question did not change the locus of the burden but instead compounded the Court’s sin in displacing OSHA’s judgment.155

Finally, in West Virginia v. EPA—the penultimate decision of Justice Breyer’s term and another Clean Air Act decision—the Court officially recognized the “major questions doctrine.”156 The Court described Brown & Williamson and its progeny as “extraordinary cases” in which “the ‘history and the breadth of the authority that [the agency] ha[d] asserted,’ and the ‘economic and political significance’ of that assertion” led the Court to require the agency to “point to ‘clear congressional authorization’ for the power it claim[ed].”157 The Chief Justice’s majority opinion was characteristically incremental: it acknowledged this burden-shifting practice and dubbed it the “major questions doctrine” but left largely unanswered the questions we have outlined above. The majority was ambivalent about whether courts should measure a question’s significance by an absolute or relative standard.158 It also justified the rule as an approximation of congressional intent but stopped just short of expressly endorsing it as a tool for enforcing the nondelegation doctrine.159 There was no mention of Chevron.

Justice Gorsuch sought to put flesh on the doctrine in his concurrence.160 He described it as a clear-statement rule designed to enforce Article I’s Vesting Clause, as well as other important structural and procedural values in the Constitution.161 He further articulated principles that could guide a court’s determinations as to whether a question is “major” and whether Congress has spoken clearly enough in authorizing an agency to answer that question.162 Confirming that the contours of the doctrine remain unsettled, only Justice Alito joined Gorsuch’s opinion.163

Justice Breyer joined Justice Kagan’s dissent.164 The opinion is a tribute to Breyer’s administrative-law jurisprudence. It emphasized the practical consequences of the Court’s decision.165 It welcomed purpose into the textualist fold.166 And it pointed to Breyer’s opinion for the Court in Barnhart to exemplify a “common sense” approach to the question whether Congress has delegated a decision to an agency—an approach that encompasses a range of evidence but is ultimately centered on the agency’s expertise.167 In applying that “common sense” approach to the Clean Air Act, the dissent echoes Massachusetts168and Breyer’s major questions opinions169 by finding in the statute’s words breadth rather than ambiguity.170 The dissent also joined issue on the nondelegation rationale for the major questions doctrine for the first time, arguing that the Constitution does not support a heightened clarity requirement for congressional delegations of major policy-making authority.171 It made no plea, however, for Chevron deference to the agency’s statutory interpretation.172 New battle lines have been drawn, and Chevron appears to have left the field.

B. . . . and Future

As the Court has grown increasingly suspicious of the powers exercised by administrative agencies, the major questions doctrine has taken shape as a rule of statutory construction that denies agencies substantive regulatory authority over questions of great political and economic significance. Justice Breyer has resisted this movement. Will his retirement allow it to accelerate?

The logical person to look to for an answer is Justice Breyer’s successor. As a lower-court judge, Ketanji Brown Jackson hewed to doctrine on questions of statutory interpretation and deference to agencies. Her descriptions of the Chevron framework acknowledge that it is not absolute but do not stray beyond Supreme Court precedent.173 She has not applied the major questions doctrine in any form, and her lone nondelegation opinion follows the modern pattern of rejecting the constitutional challenge.174 Although some have predicted that she will be a pragmatist in Breyer’s mold,175 Justice Jackson’s prior decisions contain few hints about whether she will follow in his footsteps by advocating for a more case-by-case approach to agency deference.

Justice Breyer, like Justice Scalia before him, arrived at the Court as an acknowledged expert in administrative law, and he has remained a leader in that field.176 Moreover, his case-by-case approach to the law has enabled him to concur more often and thus to exert a moderating influence on the Court’s pronouncements about administrative law. Although he may not agree with all the exceptions that have been carved out of it, the erosion of the Chevron “rule” is a testament to his influence. As the Court sets out to shape the newly recognized major questions doctrine, it is Justice Kavanaugh who seems most poised to exert an influence over its formation similar to that Breyer exerted over Chevron’s development.177

As Justice Breyer was for Justice Scalia, Justice Kavanaugh is Breyer’s foil on many issues of statutory interpretation. Chevron is one such issue.178Breyer favors introducing complexity into judicial review of agencies’ interpretations of statutes; Kavanaugh favors simplifying it. Specifically, he would eliminate statutory ambiguity as a trigger for Chevron deference.179 He has criticized the ambiguity standard for, well, its ambiguity: how much ambiguity is enough to trigger Chevron, and how do we measure it?180 In Kavanaugh’s view, the traditional rules of statutory interpretation almost always yield a best reading of the statute, and that is the meaning a court should employ in resolving the dispute before it.181 Courts should defer to agencies only when the statute is best read to direct them to do so, such as when it includes discretion-conferring words like “reasonable.”182 This means that courts will never presume a delegation of interpretive authority to administrative agencies on questions major or minor.

Even when he favored the Chevron doctrine, Justice Scalia foresaw the possible ascendancy of Justice Kavanaugh’s “best reading” approach.183 He believed textualists would arrive less often at Chevron Step Two because they would find ambiguity in the statute less often.184 Those who do not give controlling weight to the text, by contrast, would more frequently find conflicting signals that required them to give way to an agency’s judgment.185 In this sense, Scalia perhaps believed Chevron reinforced the separation of powers: so long as courts behaved like courts, they would have the final word, but if they strayed into “picking out [their] friends,” they would have to give way to the experts.186

Justice Kavanaugh’s experience in the executive branch has led him to take a less sanguine view of Chevron’s incentives. He believes that “[t]he Chevron doctrine encourages agency aggressiveness on a large scale.”187 “Under the guise of ambiguity, agencies can stretch the meaning of statutes enacted by Congress to accommodate their preferred policy outcomes.”188 And stretch they will, because it is easier than sponsoring new legislation.189 Moreover, because courts do not have a standard for assessing statutory ambiguity, they are ill equipped to counter enterprising agencies.190

Whereas Justice Kavanaugh’s pre-judicial public service occurred in Article II, Justice Breyer’s occurred primarily in Article I.191 Breyer drew heavily on his experience in the legislative branch when interpreting statutes.192 His major questions principle was born of his observation that institutional limitations lead Congress to paint in broad strokes and leave interstitial issues to administrators. Observations about executive overreach, by contrast, exerted little influence in his jurisprudence.

This leads to another point of contrast between Justice Breyer and Justice Kavanaugh: their positions on the separation of powers. Kavanaugh believes that the separation of powers is a critical safeguard of our liberties and democratic institutions.193 He has criticized the Chevron doctrine as a “judicially orchestrated shift of power from Congress to the Executive Branch”194 and has taken up the major questions doctrine (which he calls the “major rules doctrine”) as an important tool to return power to Congress.195 Kavanaugh wrote an opinion similar to Justice Gorsuch’s NFIB and West Virginia concurrences when he was a judge on the D.C. Circuit. In it, he argued that the major questions doctrine is an offshoot of the nondelegation doctrine and that, accordingly, neither an executive agency nor the judiciary should be able to conclude that Congress has given the agency authority to decide a major policy question without a clear authorization from Congress.196 Moreover, after joining the Court, Kavanaugh issued a statement in which he questioned whether Congress should be able to delegate such authority even with a clear statement.197

Unsurprisingly, Justice Kavanaugh’s answers to the questions we posed above are diametrically opposed to Justice Breyer’s.

First, what makes a question “major”? Justice Kavanaugh’s choice of terminology—“major rules” instead of “major questions”—provides the answer. In his view, the doctrine comes into play only when agencies issue “rules of great economic and political significance.”198 In other words, Kavanaugh uses an absolute, external measure of significance. He has identified a set of factors that make a rule major: “the amount of money involved for regulated and affected parties, the overall impact on the economy, the number of people affected, and the degree of congressional and public attention to the issue.”199 Questions whose significance depends on their role within the statutory scheme require no special approach: Kavanaugh’s version of Chevron will almost never give agencies the upper hand on questions of statutory interpretation in any event.200

Second, how does the doctrine interact with Chevron? Justice Kavanaugh describes the “major rules doctrine” as a simple inversion of Chevron: “while the Chevron doctrine allows an agency to rely on statutory ambiguity to issue ordinary rules, the major rules doctrine prevents an agency from relying on statutory ambiguity to issue major rules.”201 But this does not mean that Kavanaugh’s “major rules doctrine” operates at Chevron Step Zero.202 Because Kavanaugh would never presume that Congress intended an agency to determine the meaning of a statute, he does not need a doctrine to help him assess whether such a presumption should apply.203 Instead, he applies his “major rules doctrine” as a rule of statutory interpretation at Chevron Step One, where he almost always lands on a single “best reading” of the statute that precludes agency discretion. As a rule of statutory interpretation, the doctrine limits agencies’ ability to issue “binding legal rules” on matters of political and economic significance by constraining them to rely on a clear congressional delegation of authority to issue the rules.204

Finally, does the doctrine’s presumption reflect the way Congress does act or the way Congress should act? Although Justice Kavanaugh has stated that the major questions doctrine describes the way Congress is presumed to act, he also emphasizes its normative underpinnings.205 The “key reason” for requiring a clear authorization from Congress is to ensure that the people’s democratic representatives retain control over the formulation of “binding legal rules,” especially on matters of great economic and political significance.206

* * *

In recent decisions, the Court has taken the major questions doctrine in Justice Kavanaugh’s favored direction, treating it as a rule of statutory interpretation that requires Congress to speak clearly if it wishes to delegate significant regulatory powers to agencies.207 But as the opinions in West Virginia and NFIB reveal, there are still many open paths the doctrine could take, and we know from history that doctrinal paths can wind in unexpected ways. At the dawn of Justice Breyer’s tenure on the Court, Justice Scalia was Chevron’s greatest champion, and Breyer, its greatest critic. Yet today, the Justice who casts himself in Scalia’s mold on questions of statutory interpretation has called for an end to Chevron as we know it, and Breyer has defended it.

There is good reason to believe that the Court’s approach to interpreting regulatory statutes will continue to be unpredictable. At least four other Justices have expressed reservations about Chevron and delegations of legislative and judicial power.208 But this potential majority does not speak with one voice.

Justice Kavanaugh’s proposed method—sidelining Chevron by refusing to find statutory ambiguity—represents a comparatively moderate approach. At least two of Kavanaugh’s colleagues (Justices Thomas and Gorsuch) have advocated repudiating Chevron altogether,209 an approach with which Kavanaugh has signaled his sympathy.210 Without the Chevron doctrine, the major questions doctrine would never aid courts in deciding whether to defer to agencies. As courts independently interpret statutes, however, they might continue to employ the major questions doctrine as a rule of construction that disfavors reading statutes to give agencies significant policy-making authority. In practice, this approach would only depart modestly from Kavanaugh’s, as, again, he would defer to agencies relatively infrequently.

Should Chevron stagger on, however, a separate trend could increase the frequency with which the major questions doctrine determines whether the Court defers to an agency’s interpretation.211 Justice Gorsuch has allied with Justice Kagan to promote a more literalist variant of textualism that runs counter to Justice Kavanaugh’s efforts to eliminate statutory indeterminacy.212 In his dissent in Bostock v. Clayton County, Kavanaugh criticized the majority opinion’s literalist approach on the ground that it displaces the ordinary meaning of phrases with the sum of individual words’ dictionary definitions, which in turn undermines efforts to “make sense” of the statute through traditional tools of statutory interpretation.213As Justice Breyer himself acknowledged, these tools can make the difference in whether one finds a statute to be clear or ambiguous.214 And although they may not concur with Kavanaugh’s characterization of their approach, Kagan and Gorsuch have readily acknowledged that their literal textualism will likely lead to consequences that were not anticipated by the enacting Congress.215 The consequent loss of statutory coherence seems likely to result in greater ambiguity.216 That ambiguity, in turn, could give the canon variant of the major questions doctrine a role even larger than the one Kavanaugh envisions. That is, it could increase the frequency with which the Court finds several “plausible” interpretations that would grant an agency policy-making power but then selects a narrowing construction on major questions grounds.217

Nor is Justice Kavanaugh’s “major rules” approach to the nondelegation doctrine (i.e., reinvigorating the nondelegation doctrine through the use of the major questions doctrine) guaranteed to prevail. While there are at least five votes to strengthen the nondelegation doctrine,218 there is no single answer about how to do so.219 In an opinion joined by Chief Justice Roberts and Justice Thomas, Justice Gorsuch identified three “important guiding principles” that should inform the Court’s approach to that doctrine.220 One principle traces its roots to Chief Justice Marshall’s opinion in Wayman v. Southard: “[A]s long as Congress makes the policy decisions when regulating private conduct, it may authorize another branch to ‘fill up the details.’”221 Is this a major questions principle?222

Justice Thomas has suggested otherwise, arguing that Wayman is consistent with an understanding of Article I that requires Congress to create all “rules of private conduct,” large or small.223 If Thomas’s view prevails, then the major questions doctrine will become much less important as a rule of statutory interpretation. The major questions doctrine is able to coexist with the present nondelegation doctrine—which allows Congress to delegate policy-making authority to agencies so long as it provides an “intelligible principle” to guide the agency’s exercise of that authority—but the rules-of-private-conduct version of nondelegation gives the major questions doctrine much less scope. That is because any “rule of private conduct” of any degree of economic or political significance will have to come from the people’s representatives, regardless of how clearly Congress expresses its desire for an agency to make the rule instead.

Where do the proponents of the nondelegation doctrine stand on this divide? Notably, although they joined Justice Gorsuch’s dissent in Gundy, both the Chief Justice and Justice Thomas stopped short of identifying the major questions doctrine as an offshoot of the nondelegation doctrine in West Virginia.224 Justice Kavanaugh’s major questions writings notwithstanding, it is not at all clear that he disagrees with Thomas that the nondelegation doctrine, whatever it requires, applies equally to questions large and small.225 As a proponent of legal rules that confine the branches to their constitutionally defined lanes, Kavanaugh may well grow suspicious of the major questions doctrine as a judge-made rule that empowers courts to decide what is major and what is not—or to reshape statutes in a way that may be at odds with congressional intent.226 Perhaps it was this concern that led him to refrain from joining Gorsuch’s West Virginia and NFIB concurrences, despite having endorsed many of the principles articulated in those opinions. Or perhaps he simply favors a more cautious approach—one that says no more than is necessary to decide the case before the Court. Only time will tell.

Conclusion

As Justice Breyer resumes his role as a professor of administrative law at Harvard Law School,227 he will continue to shape our understanding of the relationship between Congress, the courts, and the administrative state. Optimism has always been an important ingredient of Breyer’s approach to administrative law. His approach exhibits a progressive faith in technical expertise and the perfectibility of our institutions,228 which makes him less concerned than many of his former colleagues about preserving the structures the Founders erected to control man’s inherently imperfect nature.229 We respect Breyer’s starting presumption of good faith. It is a critical—and eroding—virtue in our constitutional democracy.230 We look forward to his continued contributions in that vein. But we also agree with Justice Kavanaugh that we should not dispose of the structural protections that guard against bad faith or misguided good faith, even if doing so seems likely to lead to the best outcome in a given case. Is the major questions doctrine one of those structural protections?

Justice Breyer developed his major questions principle as a way for courts to help Congress achieve its desired ends. To the extent that Breyer dispensed (or dispensed with) that principle to form a presumptive congressional intent, he assumed Congress had the ultimate goal of regulating for the public good—as revealed to the court in the facts of a given case. In Breyer’s eyes, the facts usually reveal that Congress and the courts best serve the public good when they allow the “experts” at agencies to make policy, even—and perhaps especially—on questions of great economic and political significance.

Justice Breyer’s major questions principle has developed into a doctrine that may shape congressional intent in a very different way, one that makes it more difficult for Congress to empower agencies to answer questions of great economic and political significance. How heavy a thumb the doctrine will place on the scale may well depend on Justice Kavanaugh. He has positioned himself between the two emerging approaches to the doctrine: the Chief Justice’s cautious search for “clear authorization” in “extraordinary cases,” and Justice Gorsuch’s more robust “clear statement rule” that applies to a wide range of “major” questions.

For now, Justice Kavanaugh has cast his vote with the Chief Justice, and we see the wisdom in his caution. The Chevron doctrine was once hailed as a cure for the ailments within our system of government caused by an overly muscular judiciary. Those jealous of the separation of powers came to rue its side effects. The major questions doctrine may remedy those side effects and other delegation-related maladies besides. Or it may create another unintended imbalance.

What was true when Chief Justice Marshall penned Wayman remains true today:

The line has not been exactly drawn which separates those important subjects, which must be entirely regulated by the legislature itself, from those of less interest, in which a general provision may be made, and power given to those who are to act under such general provisions to fill up the details.231

The line-drawing pen is in the hands of an ever-shifting majority and, for that reason, the future of the major questions doctrine remains very much up for grabs.

Judge Griffith served as a judge on the U.S. Court of Appeals for the D.C. Circuit from 2005 to 2020 and is now a Fellow at the Wheatley Institute at Brigham Young University, a Lecturer on Law at Harvard Law School, and Special Counsel at Hunton Andrews Kurth LLP. Ms. Proctor is a Fellow at the University of Missouri School of Law and the Kinder Institute on Constitutional Democracy and Of Counsel at Cooper & Kirk PLLC. The views presented in this Essay are our own. We thank Anthony Guttman for his superb research assistance and insights, Aaron Nielson, Kristin Hickman, Shannon and Shawn Nix, and Robert Covin for their thoughtful comments, and the Yale Law Journal for the invitation to participate in this tribute. We also wish to express our gratitude and admiration for Justice Breyer’s career of public service to our country.