This is why Trump is still fairly competitive despite his soul-sapping faults. Even now, a barely competent performance — of the sort many supposed Jeb Bush might ride to the White House — will keep Trump in the game. Not because Americans are bigoted idiots, but because the ruling class is tanking, and because Hillary Clinton, in a perfect illustration of why she is now the chief representative of that class, can’t run a campaign that will turn its image around. If she beats Trump, it will only be because Trump beat himself first.

Reasonable people surely know that it is in fact ridiculous to physically wall off Mexico, no matter who pays for it. But it is equally suicidal to rebrand the GOP as the one faction in the culture wars that doesn’t get a seat at the identity politics table.

Trump proved on Wednesday that he just might be capable of accepting those lessons. He proved he could hang with a Mexican president. He used that proof to prepare the ground for his immigration address. And then he delivered a speech whose sharp tone would fire up his base, but whose policies were actually more narrow in scope, and might just make him more palatable to moderate voters.