Last week, the Supreme Court decided two big AdLaw cases, both having to do with agency discretion and judicial deference. Decker v. Northwest Environmental Defense Council dealt with the question of whether an agency (here, the EPA) gets judicial deference when it interprets its own regs—as opposed to its organic statute, where it gets Chevron deference. (For an earlier piece on a different aspect of Decker, see here.) The traditional answer has been “yes.” That’s called Auer deference, and the Decker Court applied it (and upheld the agency). The lone dissenter was Justice Scalia, who has come to the conclusion that Auer deference shouldn’t exist. The basic idea: Auer deference invites the agency to write vague, ambiguous, and overbroad regulations, and that makes no sense. For my money, he’s exactly right. Chief Justice Roberts, joined by Justice Alito, submitted a concurrence, saying he’d be happy to revisit Auer—just not in this case, without full briefing by the parties. So the bar has been invited to mount a frontal attack, and that case will come soon in this theater. Jon Adler and Sasha Volokh have more here and here.