As John Sides notes at Ten Miles Square, a new survey from YouGov indicates that the birther concept, which lost ground when the president’s long-form birth certificate was released, is back, strong as ever.

YouGov’s Adam Berinsky reports that not only has birtherism made a general comeback, but it’s also reassumed its position as a plurality conviction of self-identified Republicans. As Berinskly comments blandly:

These results again demonstrate that rumors and innuendo remain powerful forces in American politics. Once set loose, they are hard to undo.

No kidding. It’s important to understand that this isn’t just some natural, healthy exhibition of the “polarized” partisan tendency to think the worst of the opposition. Many Democrats may well believe Mitt Romney is a robotic corporate shill who would govern the nation horribly. But no one thinks he wasn’t born where he says he was born, or is not constitutionally qualified to serve as president.

Maybe I’m wrong about this, but were someone to start a rumor that Romney was actually born in Mexico as part of a secret rite whereby his parents swore allegiance to the polygamist views of their own forebears, and then hustled over the border to assume full American citizenship, I don’t think anything like a plurality of Democrats would buy it. They think Mitt’s an alien from normal American middle-class life, but wouldn’t take “alien” literally. That’s the big difference between “polarized” partisans these days.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.