President Trump has exceeded Obama’s executive willfulness, which at least strove for a patina of implausible legality. Last month, Trump said that, absent Republican success in replacing the ACA, he might end the payments “very soon.” Clearly, he thinks either spending or not spending unappropriated billions is a presidential prerogative.

The Constitution — yes, that again — says that presidents “shall take care that the laws be faithfully executed.” The framers, who were parsimonious with words, perhaps included the adverb for the reason Noah Feldman of Harvard Law School suggests: “The Constitution recognizes that the president can’t necessarily enforce every law. But it requires a good faith effort.” So, the intent of any non-enforcement matters: Is it to husband scarce enforcement resources? Or is it to vitiate a law?