Herman Cain isn't fighting this charge effectively, so he's decided to turn the attack away from him and onto Rick Perry.
Everyone can see this tactic for what it is.
As someone who, at one time, supported Perry, I can tell you that most of us do see the tactic for what it is: justified. Perry's fingerprints are all over this. Within 72 hours, this will turn into much less about Cain and will have Perry on the defensive trying to spin his baseless attack on a fellow candidate through a smear campaign. I'll call a spade a spade: Perry is dead wrong on this and in it up to his elbows.
..because there are significant numbers of voters who see it as an obvious dirty trick to get rid of Cain.