From a reader:
I think Rudy and Romney are in opposite ends of the same boat: their current ranking in national polls reflects how little most voters actually know about them. This is good for Rudy at present, but the intense scrutinized exposure of a national campaign is going to hurt him. On the other hand, Romney is currently low in the polls because of lack of name exposure and/or misconceptions regarding his being from Massachussetts and being LDS. However, he and Rudy will be switching places in the boat, so to speak, because as more get to know him he will become a person instead of a stereotype, and his place in the polls
will reflect this. As for McCain and Gingrich, most people know who they are, and it is unlikely their images will change much. I’d say the potential for momentum is on Romney’s side more than any other candidate, and 2006 testifies of that.