On March 20, 2013, the U.S. Supreme Court decided Decker v. Northwest Environmental Defense Center. On its surface, the case concerned whether runoff from logging roads required a permit under the Clean Water Act. Not far beneath the surface, however, was whether the federal courts had to defer to the Environmental Protection Agency’s interpretation of its own regulation. In the end, in an opinion by Justice Anthony M. Kennedy, the Court upheld EPA’s interpretation, relying in part on its earlier ruling in Auer v. Robbins, 519 U.S. 452 (1997), that agency interpretations of their own regulations are deferred to unless they are plainly erroneous or inconsistent with the regulation.

Obviously, there is a lot of "Auer deference" in the many shelf-feet of Federal Reporters. Simply stated, Auer is to regulations as Chevron U.S.A. Inc. v. Natural Resources Defense Council Inc., 467 U.S. 837 (1984), is to statutes.

Justice Kennedy wrote for himself and five other justices. Justice Antonin Scalia dissented in part and dedicated much of his opinion to a broad rejection of Auer. In his view, it is for the courts to decide what regulations mean, and to allow an agency to make such determinations on its own would violate the separation of powers. Chief Justice John G. Roberts Jr. and Justice Clarence Thomas concurred with Justice Kennedy’s opinion, but laid the groundwork for reconsideration of Auer. According to them, "[t]he issue is a basic one going to the heart of administrative law." This is not simply telegraphing a readiness to revisit the case; they came right out and said it: "The bar is now aware that there is some interest in reconsidering" Auer and similar cases, "and has available to it [in Justice Scalia's opinion] a concise statement of the arguments on one side of the issue."

A reader might have mixed reactions to this exercise. On the one hand, at least the Court — or a minority — is being candid about its willingness to revisit a precedent. This means litigants will be able to raise the issue in the lower courts if they wish, and will be alert to the need to dedicate more than a stray footnote to it. If that’s what justices are thinking, letting the bar and lower courts know seems to be only fair and a good idea, unless you think judges of a court of last resort ought to be essentially reactive, rather than suggesting lines of argument for counsel to advance in future cases.

The Senate Judiciary Committee is ordinarily very alert to identify points on which a nominee for the federal bench might have an agenda. Does this latest development suggest that that concern applies only to nominees and not to sitting jurists? What if a future nominee to the Supreme Court were asked her opinion of Auer? Would she have to bite her tongue, or could she, like Chief Justice Roberts and Justices Scalia and Thomas, safely ‘fess up and admit that she agreed with them that Auer should be revisited? At least the Chief Justice and Justice Thomas had the good grace to point out that only one side of the argument had been presented about Auer.

Beyond the question of activism and agendas, however, lies the question of what the allocation of powers among the three branches would be like if Auer’s fateful hour has indeed come. Plainly, power would flow massively away from federal agencies, both independent and those located within the cabinet departments. That flow of power would run in favor of the judicial branch. To be sure, agencies could fend off this shift simply by being more meticulous in drafting regulations so the opportunities for judicial big-footing would be reduced. Or they could resist the temptation to adopt interpretations that are not the most obvious or likely ones based on the plain meaning of the promulgated text. Dictionaries would start flying off the shelves in Washington. Either way, government would never be the same. (Memo to Congress: Chevron is next.)

Then again, six justices had the chance to agree with Justice Scalia or the Chief Justice and Justice Thomas, so none of this may come to pass. Might two more emerge in the next case?•