I agree with Williams, Cain will get a LOT of the black vote in large part because blacks do not support gay marriage and they are the main reason prop 8 won in CA. They came out to vote for Obama, and while they were there voted for 8 too. I received a flyer in the mail just prior to the election, a flyer directed at blacks in favor of prop 8 pointing out that Obama was against gay marriage. The fact that he supported repeal of DADT and and beat his chest over it is going to hurt him badly if Cain gets the nod.
If it was a white conservative vs. Obama, forget it.
That said, Cain could be the type of guy to convince the black voting populace of their sin of voting black instead of conscience. If that works the Republican Party and America could be in for a real awakening.