The polls may not change much. Cain is much like Clinton: there is a core of hard-core supporters that will support him no matter what he does, no matter what stupid things he says, and no matter how many times he plays the race card.
True believers die hard.
No. It is only that many of us would abandon him if a) the charges were true, and b) came from a reputable non-liberal, non-muckracking blogging source. This, my dear, does not make us cultists in the least.