John McCain’s gone full birther!

On Ted Cruz, that is. McCain, who himself was born on U.S. territory in the Panama Canal Zone, says Cruz’s birth in Canada (to an American mother and Cuban father) is “worth looking into.”

“I think there is a question,” McCain said on Phoenix radio. “I am not a constitutional scholar on that but I think it’s worth looking into. I don’t think it’s illegitimate to look into it.”

This is an odd turn, in part because McCain is one of the few high-profile members of the Republican Party who has actively denounced birtherism when directed at Barack Obama. Why the change?

Part of it stems from the fact that Cruz and McCain have disliked each other for years. McCain famously called Cruz and other, less militarily adventurous members of Congress “wacko birds” when they filibustered John Brennan’s nomination to direct the CIA over the Obama administration’s drone policy. 

But there’s more going on here. McCain’s in cycle right now, and vulnerable to a primary challenge. Normally it’d be a mistake to attack a conservative leader like Cruz if the goal was to protect your right flank. But thanks to Donald Trump and his supporters, Cruz birtherism now has a meaningful constituency on the right

It’s fitting that the man who brought us Sarah Palin would try to salvage his political career by tapping into the same reservoir of nativism that’s floated Trump to the top of the Republican primary field.