I don't think Jeb Bush's endorsement of Ted Cruz is as much of a surprise as people might think.
There might not have been much love lost between them, but Cruz never insulted Jeb's wife the way Donald Trump did.
In all honesty, the moment Trump trashed his spouse, Jeb should have slugged him right then and there on the debate stage. It honestly couldn't have done him any worse. But Jeb didn't slug Trump and Jeb is out of the running. Meanwhile, Trump is insulting his way to the presidency or at the very least the GOP nomination.
Yet the last thing Ted Cruz wants is to become the darling of the Republicand establishment and nobody gets more establishment than Jeb Bush. Ted Cruz made his reputation by being openly disdainful of the Republican establishment. Having the Republican establishment (Lindsey Graham, Mitt Romney and now Bush) embracing him will have the likely effect of driving more Republicans into Trump's arms. In a way, by endorsing him, the Republican establishment is getting a kind of revenge on Cruz. Well, sort of.