But it turned out that Republican voters didn’t want True Conservatism any more than they wanted Bushism 2.0. Maybe they would have wanted it from a candidate with more charisma and charm and less dogged unlikability. But the entire Trump phenomenon suggests otherwise, and Trump as the presumptive nominee is basically a long proof against the True Conservative theory of the Republican Party.

Trump proved that movement conservative ideas and litmus tests don’t really have any purchase on millions of Republican voters. Again and again, Cruz and the other G.O.P. candidates stressed that Trump wasn’t really a conservative; they listed his heresies, cataloged his deviations, dug up his barely buried liberal past. No doubt this case resonated with many Republicans. But not with nearly enough of them to make Cruz the nominee.

Trump proved that many evangelical voters, supposedly the heart of a True Conservative coalition, are actually not really values voters or religious conservatives after all, and that the less frequently evangelicals go to church, the more likely they are to vote for a philandering sybarite instead of a pastor’s son. Cruz would probably be on his way to the Republican nomination if he had simply carried the Deep South. But unless voters were in church every Sunday, Trump’s identity politics had more appeal than Cruz’s theological-political correctness.

Trump proved that many of the party’s moderates and establishmentarians hate the thought of a True Conservative nominee even more than they fear handing the nomination to a proto-fascist grotesque with zero political experience and poor impulse control. That goes for the prominent politicians who refused to endorse Cruz, the prominent donors who sat on their hands once the field narrowed and all the moderate-Republican voters in blue states who turned out to be #NeverCruz first and #NeverTrump less so or even not at all.

Finally, Trump proved that many professional True Conservatives, many of the same people who flayed RINOs and demanded purity throughout the Obama era, were actually just playing a convenient part. From Fox News’ 10 p.m. hour to talk radio to the ranks of lesser pundits, a long list of people who should have been all-in for Cruz on ideological grounds either flirted with Trump, affected neutrality or threw down their cloaks for the Donald to stomp over to the nomination. Cruz thought he would have a movement behind him, but part of that movement was actually a racket, and Trumpistas were simply better marks.

Cruz will be back, no doubt. He’s young, he’s indefatigable, and he can claim — and will claim, on the 2020 hustings — that True Conservatism has as yet been left untried. But that will be a half-truth; it isn’t being tried this year because the Republican Party’s voters have rejected him and it, as they rejected another tour for Bushism when they declined to back Rubio and Jeb.