In The Wall Street Journal, Karl Rove continues the fantasy of the GOP establishment: “At this stage, stopping Donald Trump from winning the nomination will require Republicans to vote strategically, casting ballots for the non-Trump candidate best positioned to win each state. That’s easy to suggest; it’s a lot harder to pull off.”

No, no, no: if John Kasich wins Ohio (possible, the latest Fox News poll has him up by 5 points) and Marco Rubio wins Florida (this morning’s Fox News poll shows him getting creamed by 23 points), then it continues to be a four-man race, which means Trump will win the winner-take-all states with his 35 to 40 percent share of Republican Party voters.

The only way to beat Trump is to get the race down to two horses. You beat a horse with a horse. If any other candidate but Ted Cruz had emerged as the non-Trump in the race, they would be rallying around him and pressuring the other guys to get out.

I have to believe a determined refusal to support conscience protections for gay marriage dissenters by Paul Singer and others of the donor class is a huge part of the reason.

Being personally ticked off doesn’t explain how big this betrayal — this refusal to get their candidate out of the race — has been.

They must think Cruz is as bad as Trump for reasons mysterious to anyone watching from the outside (and as Lindsey Graham has acknowledged, “He’s at least a Republican conservative”). Cruz may or may not win, but he won’t embarrass the party he leads — he currently ties Hillary Clinton in the polls, and he has run a disciplined campaign.

Only the resistance of the donor class can explain the failure to rally around Cruz. Why? Why?

Maybe I’m wrong about the why, but it’s a mystery.

Maggie Gallagher is a senior fellow at the American Principles Project.