118 Yale L.J. 64 (2008).

Who should ensure that statutes are interpreted to reflect background norms left unaddressed by Congress—norms like respect for the rights of regulated parties, protection of the interests of states and Native American tribes, avoidance of government bias, and the separation of powers? On the one hand, courts have traditionally sought to protect these constitutionally inspired values by applying “normative” canons of construction. On the other hand, after the Supreme Court’s Chevron decision, authority to interpret unclear regulatory statutes generally belongs not to judges, but to agencies. This question has polarized courts and commentators. A majority, including the Supreme Court, adopts a categorical approach in which canons “trump” Chevron, displacing the agency’s interpretive role altogether. A minority, including the Ninth Circuit, concludes the opposite: that courts should not apply canons, but instead should leave full interpretive discretion to agencies. This Article rejects both categorical approaches and proposes an alternate analytic framework. It argues that whether an agency policy comports with background norms should be considered as part of Chevron’s case-by-case, step-two inquiry into whether the policy is reasonable. Unlike the categorical approaches, this context-sensitive solution creates incentives for robust agency norm protection in the first instance, but also permits courts to apply normative canons independently when administrative decisionmaking either offers little advantage, or fails to account for the background values it implicates. This solution also cabins judicial discretion to resolve broader policy questions and compels courts to be clearer about when, and why, different canonic formulations should apply and the implications for agency input. In sum, it best enlists the capacity of the administrative state to promote accountable and informed deliberation on the balance between regulatory goals and norms of constitutional dimension.