I am looking at this as a way of Clinton saying that he does not like Obama, in fact, him and Hillary both hate him. Obama is the only one saying bad things about Romney and his record at Bain (well except for MSNBC, but they would tell everyone the sky is falling if Obama said it was). Anyone with a brain knows that Obama has no room to talk, since his record is worse than Romney's ever could be.
It would be beautiful if Both Clinton's voted for Romney. That would such a kick in the teeth for Obama. I would love it.