What I think is going on here, at least partly, is that the peddlers of anti-progressive lies are managing to convince a certain kind of American — white, socially conservative, etc. — that the hate-mongers are people like them; and, even more important, that progressives are Those People, people not like them.
Obama’s skin color makes this easy; but the Clintons faced the same kind of thing. Why? Well, the old line about Clinton being the first black president gets at something: even if Bill Clinton had a regular skin and name, he was obviously comfortable with people who didn’t, which made him one of Them.
And anti-intellectualism is also part of it.
In any case, it’s scary: you’ve got a good segment of the American population that is completely impervious to any kind of evidence, any rational argument. I mean, who collects statistics? People in black helicopters!