The great mystery of the Republican primary was the preference GOP elites had for Donald Trump over Ted Cruz.

Top Republicans were terrified of Trump — they thought him an erratic, narcissistic bigot who cared nothing for conservatism and could destroy the GOP for a generation. But even as it became clear that uniting around Cruz was the party’s only chance to stop Trump, they couldn’t bring themselves to do it. In the New Yorker, Sen. Susan Collins, a Republican from Maine, told Ryan Lizza why:

"With Ted, I’ve seen over and over again his playing to outside groups rather than trying to work with his colleagues," she told me on May 6th. "Those are words I probably should not say, since he’s going to come back and be one of my colleagues." She said, "But I think, because I know Ted Cruz, and I don’t know and have never met Donald Trump, that with Donald Trump I hope he can minimize his weaknesses, change his approach, knock off the gratuitous personal insults, and draw on his strengths."

In other words, it really was personal. Republicans who had worked with Cruz simply hated him. They didn’t disagree with him or fear him — they just didn’t like him, because rather than work with them in the Senate, he had mobilized outside interest groups to pressure them.

This dovetails with Andrew Prokop’s explanation, which proceeds from the fact that Cruz spends the beginning of his book calling his colleagues liars. With Cruz, top Republicans knew they would get a candidate — and maybe a president — they disliked, didn’t want to work with, and didn’t want to see rewarded. With Trump, there was at least some outside chance that this was all an act and in office he would be a reasonable dealmaker.

This wasn’t born of confusion about Trump’s downside. Collins actually asked Lizza to call her again if Trump said something crazy between their interview and the publication of the piece:

"If he says, ‘On Day One I’m going to drop a bomb on North Korea,’ " she wanted a chance to respond. "I mean, with him, you just don’t know."

So that’s how much top Republicans hated Ted Cruz. They were more willing to take a chance on the guy who might announce a nuclear war with North Korea than to unite behind Cruz, who they felt had been a real jerk in the Senate.

Politics is a strange, strange game.

The political science that predicted Trump's rise