No. It’s about conservatism. I wouldn’t support Romney just because he was ahead, because he’s not a conservative. But if it’s 2 conservatives with only slight differences, I’ll pick the one who can win.
You must have a pretty reliable crystal ball. Or maybe not, since you’re having to change horses. IMO, Romney’s chances are better if the field narrows too quickly; he has the resources. Obama wants to know who his opponent will be ASAP for the same reason.