SZCZECIN — A Europe that was already on the brink of war seemed poised to boil over into chaos on Monday, as news broke that Elmo had led a division of Panzer tanks across the Polish border.

The Supreme Court will uphold as well-established the First Amendment right to engage in ideological ad boycotts. The question is whether the Trump administration will succeed in bulldozing this as a practical matter before it reaches the high court.