I maintain that polling is inaccurate in this race, due to race: Many people will say they will vote for Obama so as not to appear “Racist” to the person taking the poll, and yet will vote for Romney when in the privacy of the voting booth.
On the other hand, it is probably best to keep in mind that this factor may be more than offset by systemic voter fraud from the Dems.
The number will be greater than zero, but I doubt "many." This sounds superficially plausible but would be a very slender reed on which to depend. I ignore the possibility in my thinking.