Less than seven weeks into Donald Trump’s second term as president, his administration has set off a new wave of handwringing over what has by now become a familiar question: has the US entered a constitutional crisis? Triggering the latest iteration of that worry, the government hastily deported more than 200 Venezuelan immigrants to a notorious prison in El Salvador, without hearings or evidence and thus without anything even resembling due process of law, pursuant to the US president’s proclamation “signed in the dark on Friday evening” that they constituted an invasion by a foreign state. Trump invoked a 1798...