With no proof.
There is a difference between that and a flat out personal accusation by Cain himself with NO PROOF.
You don’t need proof for a suggestion, just evidence of some sort. If you had proof, you could say it.
There have been multiple threads posted here, some by Cain supporters, saying that they believed Romney was behind this. You couldn’t have missed them. SO obviously, there is some evidence for it, even if there isn’t an e-mail tying them to it. Not enough to accuse them directly, but certainly enough for one campaign to question why Cain is pointing at Perry and not at Romney (which appears to be the point).