Ted Cruz did himself damage. By the end of his tireless campaign for the nomination he was semi-endearing. Wednesday night he resurrected Snaky Ted. He spoke highly of freedom and went after President Obama. Sometimes he half-laughed after speaking a line, as if to say You know this is showbiz, right? It showed an unbecoming detachment. He told the audience not to stay home in November but vote for the right person, then forgot to say who that person might be.

If you can’t endorse, good for you and stay home. That isn’t politics, it’s basic human comportment. If someone you’re certain is awful invites you to a party, you politely decline. You don’t go, walk into the room, and punch your host in the head. Mr. Cruz miscalculated, thinking if he snubbed Trump half the delegates would cheer. Instead almost all booed. He thought the media would laud his courage and integrity. They saw him as wounded and treated him as prey.

When his campaign ended in June, I attended a small dinner in his honor. Mr. Cruz was charming, modest and funny. When we said goodnight I told him I felt, in retrospect, that I hadn’t always been just to him and was glad I’d have a chance to be more generous in the future. Apparently I will need still more time. What a jerk.