Those are the times when we seek out something—anything—with enough similarity to the new person or thing, to guess what we are dealing with. We see that in the current search for something Trump-like in our past, to help get a handle on the Trump in our present. Some have been wild enough to compare him with Hitler—which is simply absurd. Comparisons with lesser figures are not very helpful, either. Some dredge up bragging demagogues like Senator Joe McCarthy and Governor George Wallace. But neither of them rose as high as the presidency. And both of them had some concept of law, of which Trump is oblivious. (Both McCarthy and Wallace not only were lawyers but had been judges.)

Thus the default comparison has become with Richard Nixon. Rumors (or hopes) of impeachment have brought back onto the stage the whole cast of surviving players from the Watergate affair. There are some superficial resemblances between Trump and Nixon. Trump, like Nixon, has bottomless reserves of self-pity. Nixon, like Trump, was contemptuous of the press. But the dynamics in their cases are entirely different. Nixon pitied himself because the press fawned on the Beautiful People—jet-setters of the time. (How is it fair that fate made John Kennedy handsome and left me looking goofy?) Trump pities himself because the press will not pay unanimous homage to the most beautiful person in the world (who has the biggest jet of all). Trump openly loves himself as much as Nixon secretly loathed himself.

Another resemblance is their humorlessness. Senator Al Franken, an expert on laughter, noted early on that Trump does not laugh easily, if at all. He can sneer at Lyin’ Ted or Crooked Hillary, but others, not he, are supposed to laugh at this. Nixon, who was not spontaneous at anything, could not laugh spontaneously. Esquire magazine ran an annual feature with the caption “Why is this man laughing?” next to an awkward picture of Nixon in mad cachinnation. Nixon was too guarded to laugh (“Are they laughing at me?”). Trump is too pompous to break his mien of majestic superiority. There is a kind of rough equality in laughter, a sense that we are joining the club of humanity.

The worst thing journalist Murray Kempton could say of any man was that “he has no sense of sin.” Nixon knew he had sinned but pleaded that it was in self-defense against all the anticipated sins of his enemies. Trump admits the Bible is a good book, but he cannot read it, since his name is not in it. A friend of mine used to say of an acquaintance that he had “an overdeveloped instinct of self-preservation.” That was true of Nixon. He had to mount defenses against anticipated attacks from all sides. In Trump, the need for self-adulation has overwhelmed his sense of self-preservation. He will do things to assert his magnificent magnificence, which only exposes him to greater peril (including the peril of looking ludicrous). He sees things no one else does: Muslim crowds cheering the Twin Towers down, record crowds at his own inauguration, all the “illegal” voters bussed into New Hampshire, the many blacks and Muslims who like him. He erases from his mind anything that does not please him at the moment. He promised to give up all his business ties, as so much “peanuts” compared with the office of the presidency. (He has given up nothing; in fact he is busily adding to his riches.) He would, we were told, be so hard at work in the White House he could not go near a golf course. He would release his tax returns—but only when an elusive audit was completed or when Hillary released all her e-mails. Apparently we are to learn the full horror of what we have put in the Oval Office only when he leaves it....