Justice Thomas's concurrence in Ellingburg v. United States (Jan 20) is gorgeous. It doesn't counter—but powerfully confirms—the argument I made in Constitutional Illusions & Anchoring Truths on ex post facto laws. Thomas is on the right track...but he doesn't take it all the way. Thread 👇 Thomas rightly sees that for many Founders, the Constitution’s general bar on ex post facto laws wasn't confined to criminal matters. He reads Calder v. Bull that way. In Fletcher v. Peck, John Marshall found the deeper ground—by drawing the Contracts Clause deductively, from the even deeper principle on ex post facto laws. 2/