And when your opponent hands you a gift like Hunter Biden, whose drug-fueled influence peddling, remember, was first reported by mainstream institutions like the New York Times, ABC News and the New Yorker, don’t turn the story back on yourself with a foolish and unnecessary call to the Ukrainian president. Shut up. Let the media carry the ball. Would Hillary have made this mistake? Did she put her fingerprints anywhere near the Steele dossier? Of course not. And when Hunter’s laptop surfaced, the mainstream press would have covered it because Hunter was still their story.

Mr. Trump was the most known person ever to run for the presidency; he spent 40 years advertising his gaucheries to the American people. His outsider act was central to his appeal, but that hardly required coming up short on political calculation, discipline and patience. Mr. Trump plays checkers. The game is chess. His slim loss in the Electoral College should rankle, all right, because it shows how different the outcome might have been if he had done a few little things differently—including listen to advice.