Also scary for some power brokers is a person in the office of President that they can’t control. Think of the classic mobster blackmail of getting a picture of a local politician with a hooker. The mobster keeps the pictures to himself, but calls in favors every once in awhile on threat. And uses the carrot of campaign contributions and bribes on the other side.
I think this is part of the reason I like Romney so much. He is in control of himself. In every religious philosophy and tradition, a main goal for liberation/enlightenment/mystical union is the conquest of self. The man who conquers himself is truly free. The man who has not is a slave to his passions.