All government officials take an oath to uphold the Constitution. The Supreme Court is the ultimate authority on the interpretation of the Constitution and, more pointedly, when a law or official conduct is unconstitutional. But the Court doesn’t decide all those questions. And so executive officials are often left with unanswered questions about whether a law or course of conduct is constitutional. The official might conclude that the law or conduct is unconstitutional and thus refuse to enforce or engage in it. Or the official might conclude that the law or conduct is constitutional and thus enforce or engage in it. If wrong, however, the official could be sued or prosecuted.

Officials often rely on nonjudicial authority to provide guidance in these instances. For example, the Office of Legal Counsel and the Attorney General provide opinions about the constitutionality or unconstitutionality of certain laws or conduct. The President may issue a signing statement that memorializes an opinion that part of the law is unconstitutional. When lower-level officials rely on these opinions, can they use that reliance as a legal defense if sued or prosecuted?

Professor Zach Price interrogates that question in a new article titled “Reliance on Executive Constitutional Interpretation,” forthcoming in Boston University Law Review. He proposes that the answer should vary depending upon the context and should be informed by three principles. The first principle is fairness and cuts in favor of a defense: it would be unfair to subject an official to liability for following an objectively reasonable opinion from the office authorized to give it. The second principle is anti-suspension and cuts against reliance: the separation of powers restricts the authority of the executive branch to suspend (decline to enforce) legal requirements. And the third principle is departmentalism and cuts in favor of reliance: the executive branch has some authority to interpret the constitution for itself in the absence of controlling Supreme Court precedent.

In his usual way, Professor Price distills these principles from doctrine (including administrative law’s familiar Chevron and Mead doctrines) and a deep understanding of the inner workings of the executive branch. With balance and sensitivity, he then applies the interplay of these principles to create three general rules of reliance: (1) reliance on a signed and reasonable OLC or AG opinion is a defense to any government enforcement action; (2) reliance on any other executive directive, including signing statements, is a defense if the directive is consistent with closely analogous and reasonable OLC or AG opinions; and (3) reliance in other circumstances is not a defense.

The result is an impressive and important article that offers both understanding and guidance to an issue that repeatedly arises within the executive branch. This is a must-read for constitution scholars, judges, and especially executive officials.