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With Jeb Bush’s endorsement of Ted Cruz, the GOP is caught between a rock and a hard place.

Cruz is shaping up to be the last hope of preventing Donald Trump from winning the magic number of 1,237 delegates before the convention in July. Cruz won Utah, while John Kasich is running behind Marco Rubio, who is no longer in the race, in Arizona, suggesting the Texas senator is the only candidate left in the race who can plausibly claim the nomination in the event of a brokered convention. Bush appears to recognize this, saying, “Ted is a consistent, principled conservative who has demonstrated the ability to appeal to voters and win primary contests, including yesterday’s Utah caucus.” The problem for the Republican Party is that Cruz is almost as bad as Trump when it comes to being an attractive general election candidate. According to Gallup, Trump has a higher unfavorable rating (63 percent) among adults nationwide than Cruz (50 percent). But Cruz’s favorable rating (29 percent) is lower than Trump’s (30 percent). Unlike Trump, Cruz would have no shot at poaching voters from the other side; Cruz is hard right conservative politics at its purest, the embodiment of the theory that Republicans can win elections by being more, not less, homogenous and ideologically rigid. If he’s the GOP’s last hope, then that’s not much of a hope at all.