I am not suggesting another volume of Profiles in Courage here. But Profiles in Sheepish and Occasionally Effective Dissent would not struggle for case studies. In parts of the country, support for Mr Trump is as bottomless as the hype implies. In Washington, it can be gossamer-thin. Aside from any personal dislike of him, his two dearest projects — protectionism and lower immigration — jar with conservatives reared on laissez-faire. Some Republicans are even willing to put a number on the closeted apostates. Were the vote held in private, “at least 35” GOP senators would choose to convict the president, according to Jeff Flake, who was one of their number until January. They will not, of course, but the chances of a different and still lethal rebellion are underrated.

What might cause it? Were public opinion to turn decisively for impeachment — the first polls merely lean that way — it would focus minds. Were Mr Trump’s behaviour to deteriorate, his staff would have to decide whether to risk ensnarement in the mess. What put the likes of Haldeman in jail was not Watergate itself but the efforts to cover it up. And that was under a president with some grounding in the rules. Mr Trump, a neophyte in Washington, often appears sincerely dumbstruck by the illegality of certain actions.