Following up on Jamelle's post below about that New York Times poll, here's another result that reinforces what we've heard before, but it's still shocking every time:
A plurality of Republican voters, 47 percent, said they believed Mr. Obama, who was born in Hawaii, was born in another country; 22 percent said they did not know where he was born, and 32 percent said they believed he was born in the United States.
That's right: Less than a third of Republicans believe the president of the United States is American. Ben Smith says, "It seems that answering 'was Obama born in a foreign country' elicits from Republicans the sort of response from Repubicans that 'is George W. Bush a moron' would have elicited from Democrats -- a way to express reflexive hostility." He may be right about that, and the obvious difference is that whether Bush was a moron is a matter of opinion, whereas the location of Obama's birth is a matter of fact.
So think for a moment about the kind of psychological leap it takes to put oneself in the birther camp. You have to decide not just that you dislike Obama and that he's a foreigner (alien, Other, threatening) but also that almost the entire world -- not just Democrats and the media, whom you already hate but also people like Karl Rove -- are participants in a massive conspiracy whose origins date back half a century.
The fact that lots of Americans believe crazy stuff is certainly nothing new -- according to this poll, 32 percent of Americans believe we're being visited by aliens, and 26 percent believe in astrology. But it's not as though you would try to have a rational discussion with them about, say, how we should handle the budget deficit.