So Obama does well in the Zogby poll Mike just posted. But as Jake Tapper notes, there's a longstanding belief that a lot of white people lie on these surveys, telling pollsters they'll support the black candidate so as not to seem racist, only to lose their nerve once they actually step inside the voting booth. As Earl Graves warned Colin Powell, who was polling high in 1995, "Look, man, don't let them hand you no crap. When they go in that booth, they ain't going to vote for you."
So is this effect--known as the "Wilder effect"--actually real? A few weeks ago, Dave Weigel went through the numbers and concluded that it's probably not true anymore. In each of the 2006 races featuring a black candidate, polls taken right before the election closely predicted the final outcome. (On that note, see this discussion of Harold Ford, Jr.'s loss in Tennessee.) If he's right, that doesn't mean race is never a factor in elections, obviously, just that there probably aren't legions of white voters who are lying to pollsters about supporting Obama.