Loper Bright, overruling Chevron, is unmistakably part of administrative law’s current “Grand Narrative,” which sees contemporary administrative agencies with suspicion, as a product of successive breaches of Article I, II, and III of the Constitution. The decision should be seen as our Marbury v. Madison—an effort to insist that it is emphatically the province and duty of the judicial department to say what the law is. But will the decision produce large changes? The answer depends, of course, on the meaning of both Chevron and Loper Bright.