Obama and a Racial Question

Lots of folks on TV talk about voters and race. The question is generally posed as some variant of: Americans don't openly say they won't vote for a black man, but in the privacy of the voting booth will (other) Americans en masse vote for a black man? (The implication by the speaker, of course, is they would vote for a black person).

I don't "get" this assumption. If someone was racist and stupid enough to not vote for a black man because of race, why would they be smart enough to lie about it? I've never understood this assumption of secret, hidden racism lurking underneath. What is lurking beneath? Who thinks to themselves - "you know, I like what this Obama is saying, I'd vote for the guy...it's just, you know, he's black."