What’s more surprising — Jeb Bush endorsing Ted Cruz, or Ted Cruz bragging about it? After winning Utah but losing Arizona, Team Cruz sent out a statement this morning announcing the backing of the one man who most embodied the Republican establishment against which Cruz has spent his term in the Senate fighting:

“Today, I am endorsing Ted Cruz for President,” said Bush. “Ted is a consistent, principled conservative who has demonstrated the ability to appeal to voters and win primary contests. Washington is broken, and the only way Republicans can hope to win back the White House and put our nation on a better path is to support a nominee who can articulate how conservative policies will help people rise up and reach their full potential.” Bush continued, “For the sake of our party and country, we must move to overcome the divisiveness and vulgarity Donald Trump has brought into the political arena, or we will certainly lose our chance to defeat the Democratic nominee and reverse President Obama’s failed policies. To win, Republicans need to make this election about proposing solutions to the many challenges we face, and I believe that we should vote for Ted as he will do just that.”

And for good measure, Bush posted a somewhat lengthier Facebook message urging Republicans to unite behind Cruz:

As I said from the moment I launched my presidential campaign, the stakes in 2016 couldn’t be higher. Washington is broken, too many families are stuck in poverty and Western civilization is under attack from radical Islamic terrorists, as evidenced by the horrific attack in Brussels, which was preceded by attacks in Paris and California. … Republicans can win back the White House and put our nation on a path to security and prosperity if we support a nominee who can unite our party and articulate how conservative policies will help people rise up and reach their full potential. I hope you will join me in supporting Ted’s campaign by visiting www.tedcruz.org, and contributing and volunteering.

If we had video of the endorsement, it would look something like this:

This has to come as a blow to John Kasich, who must have figured to be the last candidate around which traditional GOP leadership would rally. He’s a two-term governor and a former key member of the 1994 House revolution, not a one-term Senator more known for obstruction than coordination. Kasich must be scratching his head at Bush’s full-throated endorsement today of a man who helped wrest the party away from the people who backed Bush for more than a year. It’s a pretty clear signal, though, from those same folks to Kasich: Get out.

It also sends a signal that the so-called Republican establishment sees a conservative ideologue as less dangerous than a populist upstart. Ever since the start of the Tea Party, movement and grassroots conservatives have demanded that GOP leadership acknowledge their ascendancy. Well, now Bush has done so, at least, but the differences between the two choices may not be that wide, at least for what it means to the established order in the Republican Party. If we stick with the Ghostbusters references, they’ve simply chosen the form of the Destructor — only instead of the Stay-Puft Marshmallow Man, they have Teddo the Conservatarian. (Okay, that was Ghostbusters II, but you get the drift.)

But is it too late? If Kasich takes the hint, Cruz will get Donald Trump one-on-one in Wisconsin, and we’ll see whether the combined forces of the party’s leadership and movement conservatism can keep Trump from getting to the nomination. If Kasich stays in, though, he’ll simply be the keymaster to unlocking the gate to a new ascendancy of populism within the GOP.