On that poll of extremisms, TPM Reader SR sends us this ...

My specialty is survey research, and I think you are taking these results a little too seriously. People are petulant, truculent, and belligerent. A good portion those answering in these ridiculous ways, are just giving a middle finger to a politician that they hate, either Bush or Obama. I have seen this many times, and it highly correlates with strong partisans and ideologues. But that does not mean that they actually believe it. They just think it is funny to answer a poll question in a belligerent way.

I've actually had the same thought. And I would say on two different levels.

On the "anti-Christ" question, I do think there is a non-trivial number of Republicans who think Obama really may be the anti-Christ, in the Christian eschatological sense. There are fundamental websites where the subject gets actively discussed. On the Dem side, you have to figure that a lot of the yeses about Bush are just generic abuse. And not a few Republicans about Obama too.

A slightly different issue is Obama's place of birth. In this very polarized climate, I do figure that in many cases you have Republicans who really hate Obama and just reflexively say they don't think or don't know whether he was born in the US because to say he was would be to cut him some slack. So I think SR's right that it's pretty difficult to separate out actually beliefs from generic middle-finger reaction to someone you despise.