abstract. A critical issue in any racial vote-dilution case is the proportionality (or lack thereof) of a minority group’s representation: how well (or poorly) minority voters are represented relative to their share of the population. In an important recent opinion, Judge Easterbrook proposed replacing this proportionality benchmark with what we call the “race-blind baseline.” Under this approach, minority voters’ representation would be compared not to their population share but rather to the fraction of seats they would control if districts were drawn randomly and without the use of racial data. Long critical of the proportionality benchmark, conservative advocates have been quick to embrace Judge Easterbrook’s idea. The current Supreme Court, which has already dismantled part of the Voting Rights Act, may also be interested in adopting the race-blind baseline. Yet until now, no one has explored this benchmark’s implications: how it would affect minority representation as well as the partisan balance of power.

In this Article, we tackle these questions for the first time. We do so using a technique—the random generation of district maps by a computer algorithm—that has become the gold standard in partisan-gerrymandering cases, but that has not yet been systematically deployed in the context of race and redistricting. We find, first, that in most states, a nonracial redistricting process would yield substantially fewer districts where minority voters are able to elect their preferred candidates. Judge Easterbrook’s proposal would thus cause a considerable drop in minority representation. Second, we show that the minority opportunity districts that arise when lines are drawn randomly are quite different from the ones that now exist. They are less likely to pack minority voters and more apt to represent them through coalitions with white voters. And third, contradicting the conventional wisdom about the link between minority and partisan representation, we demonstrate that Democrats would not benefit from the elimination of opportunity districts under the race-blind baseline. Rather, in the southern states where the benchmark would have the biggest impact, it is Republicans who would gain a partisan edge.

author. Jowei Chen is Associate Professor of Political Science, University of Michigan. Nicholas O. Stephanopoulos is Professor of Law, Harvard Law School. We are grateful to Chris Elmendorf, Rick Pildes, and the workshop participants at Harvard Law School, the Loyola University Chicago School of Law, Princeton University, the UC Berkeley School of Law, the University of Chicago Law School, the University of Miami Law School, and Vanderbilt Law School for their helpful comments.

Introduction

The modern era of voting rights may soon be coming to an end. For more than thirty years, courts have agreed on the baseline for comparison in a racial vote-dilution case. A minority group bringing such a challenge—asserting that its electoral influence has been unlawfully diluted by a set of district lines—must compare its existing representation to the benchmark of proportional representation. If the group is represented disproportionally poorly, in that the share of districts it controls is smaller than its fraction of the population, the group’s legal claim is significantly bolstered. Conversely, if the group already enjoys close to (or more than) proportional representation, its claim all but collapses.1

Conservative Justices on the Supreme Court, however, have never been comfortable with this approach. In their view, the emphasis on whether minority voters control a proportional share of districts is untrue to the text of section 2 of the Voting Rights Act (VRA), which disclaims any “right to have members of a protected class elected in numbers equal to their proportion in the population.”2 Even worse, according to these critics, the proportionality baseline overly racializes the redistricting process. It encourages jurisdictions to draw many districts for racial reasons, thus conveying the message that representation is primarily race based and aggravating racial cleavages in American politics.3 As Chief Justice Roberts decried in a 2006 case, “It is a sordid business, this divvying us up by race.”4

To date, the Court’s conservatives have been unable to stop the divvying. But thanks to the recent ascensions of Justices Barrett, Gorsuch, and Kavanaugh, their luck may be about to turn. There may now be a solid majority for rethinking vote-dilution law and sharply limiting the scope of section 2. If such reform were to occur, it could plausibly entail the replacement of proportionality with a race-blind baseline, asking how many districts minority voters would control if the lines were drawn without any consideration of race.5 The case for liability would then be strongest if a minority group is underrepresented compared to the outcome of a nonracial redistricting process. The case would be much weaker, though, if the group already controls as many districts as would be expected given the application of nonracial mapmaking criteria.

This substitution of a race-blind baseline for a proportional one was proposed most notably by Judge Easterbrook in the 2008 case of Gonzalez v. City of Aurora.6 Posing the question, “Diluted relative to what benchmark?,” the conservative jurist answered, “[T]he outcome of a race-neutral process in which all districts are compact.”7 He elaborated that “computers can use census data” to “generate a hundred or a thousand different maps.”8 If these randomly created maps “look something like the actual map” in their racial characteristics, then “we could confidently conclude that [the actual] map did not dilute the effectiveness of the [minority] vote.”9 But if the actual map has fewer minority-controlled districts than most of the simulated maps, then “a court might sensibly conclude that [the jurisdiction] had diluted the [minority] vote.”10

Judge Easterbrook’s suggestion has been echoed by right-wing activists11 and flagged by legal12 and political-science13 scholars. It also dovetails with the conservative critique of the section 2 status quo, being both more faithful to the statutory text (since it eschews proportionality) and less race conscious (since a race-blind baseline is, well, race blind). And just a few years after the Supreme Court eviscerated the VRA’s other key provision in Shelby County v. Holder,14 the possibility of radical change in the law of vote dilution cannot be discounted. Yet until now, no one has taken Judge Easterbrook’s idea seriously. No one has comprehensively analyzed how minority representation could be affected by the move from a proportional to a race-blind baseline. Nor has anyone studied the potential partisan implications of this shift: how the major parties could be impacted if the lines were drawn solely on nonracial grounds.

In this Article, then, we investigate these issues for the first time. We do so using the method that Judge Easterbrook outlined in Gonzalez: the random generation of large numbers of district maps by a computer algorithm, based exclusively on nonracial criteria. This technique was still in its infancy when Judge Easterbrook referred to it in 2008. In the ensuing decade, however, it has ripened to full maturity. Political scientists, mathematicians, and computer scientists have published dozens of papers introducing redistricting algorithms and applying them to various problems.15 Courts have also admitted expert testimony about randomly generated district maps—from one of us in more than ten cases16—and relied heavily on this evidence in their opinions.17 Almost all of this litigation has examined whether partisanship accounts for the differences between enacted plans and the arrays of simulated maps. No lawsuit (and no academic article) has systematically explored the effects of race-blind (rather than party-blind) redistricting. Nor has the legal literature yet employed mapmaking algorithms at anything like this Article’s scale, though they are the field’s most important development in recent memory.

We include in our study almost all states with sizeable minority populations: the ones for which section 2’s requirements are most relevant. We also conduct our analysis at the state-house level because state-house districts are more numerous than their congressional counterparts, enabling a more fine-grained inquiry. For each state we consider, we randomly generate one thousand state-house maps. These maps match or beat each state’s enacted plan in terms of traditional criteria such as population equality, compactness, and respect for political subdivisions. But unlike each enacted plan, these maps completely ignore race. Having produced these sets of comparators, we then bring race back into the picture. In the most extensive application to date of ecological inference, we estimate the voting behavior of minority and nonminority citizens, precinct by precinct, in each state. We use this data to determine the numbers of minority opportunity districts in the enacted plans as well as the simulated maps and then to compare these volumes. We define an opportunity district as one where minority voters are able to elect their candidate of choice because they outnumber nonminority voters within their preferred party, which in turn is the district’s majority party.

We find that most—though not all—enacted state-house plans overrepresent minority voters relative to the race-blind baseline. For example, numerous plans in the Deep South include substantially more African American opportunity districts than would typically emerge from a nonracial redistricting process, while a few plans in the Border South include fewer such districts. Similarly, several western states feature extra Hispanic opportunity districts compared to the race-blind baseline, while only one western state underrepresents Hispanic voters. Perhaps our most interesting result, though, has to do with the makeup (not the number) of the opportunity districts in the randomly generated maps. In most cases, these districts have smaller minority populations than the opportunity districts in the enacted plans (albeit still large enough to elect minority-preferred candidates). In other words, the enacted plans’ opportunity districts generally pack minority voters beyond the point required by law or geography.

Our findings have significant legal and policy implications. First, current plans that feature more opportunity districts than usually arise when nonracial mapmaking criteria are applied would be highly vulnerable if Judge Easterbrook’s proposal were adopted. Some of these plans’ opportunity districts could be attacked as unlawful racial gerrymanders, designed with an inordinate racial focus. States could also dismantle some of these plans’ opportunity districts with little fear of violating section 2 or the U.S. Constitution. Second, however, current plans that underrepresent minority voters relative to the race-blind baseline could still yield viable section 2 lawsuits. Even in Judge Easterbrook’s preferred regime, plaintiffs would be able to show that more opportunity districts would have materialized had the lines only been drawn without considering race. And third, in almost all jurisdictions, mapmakers could use a different strategy to satisfy their section 2 obligations (whether the baseline is race neutrality or proportionality). They could considerably unpack minority voters without sacrificing these voters’ abilities to elect their candidates of choice.

What about the partisan consequences of the race-blind baseline—how the major parties’ legislative representation would be affected by lines drawn on nonracial grounds? To tackle this question, we randomly generate one thousand more state-house maps for each state in our study. These maps again ignore partisanship and match or beat each enacted plan in terms of traditional criteria. But unlike their predecessors, these maps equal each enacted plan’s number of minority opportunity districts. They are race conscious, not race blind. In combination, the two sets of simulations allow us to estimate the partisan impact of Judge Easterbrook’s idea. The second simulation set extracts party but not race from the districting status quo. The first simulation set extracts party and race. The difference between the simulation sets thus represents the partisan effect of the race-blind baseline.

We find that, in the Deep South, Republicans would benefit from nonracial redistricting. That is, maps produced without consideration of party or race typically include more Republican districts than maps that ignore partisanship but match the existing number of opportunity districts. In the rest of the country, by contrast, Judge Easterbrook’s proposal would have minimal partisan implications. In these areas, maps in the second simulation set (extracting party but not race) have very similar volumes of Democratic and Republican districts to maps in the first simulation set (extracting party and race). So shifting from race-conscious to race-blind redistricting would leave the partisan balance of power largely undisturbed.

Our results challenge the conventional wisdom about the relationship between minority and partisan representation. For roughly a generation, many academics have believed that complying with section 2 (in particular, moving toward its proportionality baseline) advantages Republicans by overconcentrating Democrats in opportunity districts.18 These scholars would presumably expect redefining section 2 compliance (specifically, swapping a proportional for a race-blind baseline) to assist Democrats by unpacking some opportunity districts. Yet our findings directly contradict this hypothesis. In most of America, implementing Judge Easterbrook’s proposal would not improve Democrats’ electoral position at all. In the only part of the country where the parties’ lots would be affected—the Deep South—it is Republicans who would gain from the switch to the race-blind baseline.

The Article proceeds as follows. In Part I, we identify the conservative critiques of section 2’s proportionality baseline. It is these critiques that make its replacement by a race-blind baseline attractive to Judge Easterbrook and likeminded observers. In Part II, we provide more information about the random generation of district maps, a technique not previously used at scale in the legal literature. We also explain our methodology, especially our definition of minority opportunity districts. In Part III, we present our results about minority representation: how and why the race-blind baseline would influence states’ numbers and types of opportunity districts. On the whole, it would both reduce these districts’ volumes and unpack their minority voters. And in Part IV, we turn from minority to partisan representation: how and why the race-blind baseline would alter the parties’ fortunes. Here, our findings run against the grain of most prior scholarship.