Donald Trump issued his declaration of war against his “enemies within” at the Department of Justice on 14 March. Thus the president launched a constitutional crisis that encompasses not just a group of migrants snatched without due process and transported against federal court orders to a foreign prison, but a wholesale assault on virtually every major institution of American society. “We will expel the rogue actors and corrupt forces from our government. We will expose, and very much expose, their egregious crimes and severe misconduct,” he pledged. “It’s going to be legendary.” Trump’s speech condensed his mission to its despotic...