Very true. Cain would be a completely different story. Obama has been used to opponents giving him deference in political races. With Cain manning the guns at the other podium -- and using them -- Obama will find he's in a whole new dynamic... one that doesn't portend well for him.
No matter WHO debates Obama, they will be dismissed as the loser out of hand. Doesn’t matter if it’s Perry or Romney or Cain.