Herman Cain was his biggest threat BY FAR, because HE would have divided the black vote, which NOW Obama has in his pocket. I was a Cain supporter for just that reason, i.e. NOT that I thought he was so great, but a black Republican would have been the ONLY one who could beat Obama (and THAT must be the prime objective!)
That’s why Obama’s people dug up all that dirt (and who even knows how much of it was true) on Cain and forced him out.
Other than Cain, I think all the others are about equal in how much of a threat they are to the messiah, ooops, I mean to Obama.