Ted Cruz.  (C.J. Gunther/EPA)

There's an assumption among casual consumers of politics that establishment Republicans loathe Donald Trump. Not really true.  Yes, they worry about what Trump might do downballot to the GOP if he is the nominee. But most view him with some mix of puzzlement and fascination. The Republican establishment saves its actual hatred for one man and one man only: Ted Cruz.

Witness Terry Branstad, the four-term governor of Iowa and, without question, the face of the Republican establishment in the state. On Tuesday, he told reporters that he wants to see Cruz beaten in the Iowa caucuses in 13 days -- a remarkable admission by a sitting incumbent of such long standing.

Yes, I know that Branstad's reason for opposing Cruz is that the Texas senator opposes the Renewable Fuel Standard -- a key provision for Iowa's ethanol industry. (Cruz says he supports ethanol and biofuels generally but opposes all subsidies and mandates for the energy industry.) And yes, I know that Branstad's son is spearheading a group promoting biofuels and making sure the presidential candidates address the issue.

Even so, it is an amazing testament to how widely disliked Cruz is by the party establishment that Branstad is willing to go on the record against him this close to the caucuses.  Normally, if Branstad really didn't like a candidate he would either a) make that known to influential grass-roots folks and donors and let it be or b) endorse some other candidate. Branstad is saying, in essence: You can support whoever you want. But make sure it's not Ted Cruz.  To single out Cruz in that way speaks to a level of personal animus that is somewhat remarkable for politicians at this level.

This is the second time in recent weeks that Branstad has made his feelings clear about Cruz. After  Trump raised questions about whether Cruz, who was born in Canada, is eligible to be president, Branstad provided this decidedly non-committal quote:  "When you run for president of the United States, any question is fair game. So let the people decide." Branstad was far from the only establishment pol willing to form a strange alliance with Trump -- and against Cruz -- on the citizenship issue. John McCain, with whom Cruz has regularly feuded, was quick to offer up a quote that helped stoke the controversy too.

What's not debatable is the Republican establishment's outright contempt for Cruz. What's less clear -- at least to me -- is what effect, if any, it will have on Cruz's chances in Iowa or anywhere else. Branstad is popular, no question. But  Cruz will paint him as simply part of the very establishment that has screwed things up -- in Washington and in Iowa -- for years.  Of course "they" don't want me to win, Cruz will argue. They want to keep their hands on the levers of power.

Branstad coming out against Cruz  could  simply reaffirm his basic outsider message, which already has a demonstrated appeal in Iowa and elsewhere. But  regardless of its ultimate impact on the race, which we may not know until the caucuses  Feb. 1, that Branstad was willing to publicly urge voters to choose anyone but Cruz provides a telling window into the mindset of the party establishment  in regards the Texas senator. And that mindset is dislike, pure and simple.