As for former President Trump, one wants to be gracious as a man leaves—but what was departing was a national trauma.

His goodbye rally at Joint Base Andrews was intended to show the spirited and temporary receding of a titanic force. It didn’t. His remarks were wan and offhand, and the White House had to scramble to get people to come. His last words in public as president: “Have a good life. We will see you soon.” Then he flew off to Xanadu.

Shortly after, the alt-right group Proud Boys disowned him as a “total failure,” and QAnon message boards lit up. They had believed in “the plan,” when that conspiracy was always fantastical and bizarre. Now they were concussed. Mr. Trump was gone. Were we played? Yes, you were played. Now get offline and go find your life.

A final thought on Mr. Trump. It is one thing to come into the presidency with no particular class or dignity, as a person who knows “the price of everything and the value of nothing.” It is another and almost an achievement to leave the presidency like that—to have been untouched by the grandeur, unchanged by the stature and history of the office. None of it rubbed off and improved him. His supporters see this as proof of his authenticity, of his irreducible Trumpness. It is not. It is proof not that he couldn’t be reduced but that he couldn’t be enlarged.