Actually, in a devious way, playing off the "vanilla" front runners in the GOP gives him room to appeal to blacks who otherwise would never consider voting for a GOP candidate. If he puts some distance between himself and the "vanilla" republicans, that creates some room and makes it a little easier for a black democrat to cross over and support him.
BTW, if Cain could really bring anything close to the 33% black support along with him the Democratic party would be finished for good.
I am serious. They must have 85% or more or they are toast.
When it comes to racial issues, once the charge is made, the damage is done. It reflects badly on Cain.
Sadly, the Democrat plantation mentality is still running strong. Obama will get 90% of the black vote in 2012.