Hi tkc,
Romney is doomed because he's no one's second choice.
His only chance is that the Rove/Romney axis destroys the opposition using negative ads. Otherwise, the votes are headed elsewhere. That's my view, anyway.
If you want to know why it is the bubble has moved from one non-Romney to another, look no further than Fox News, which itself has focused its support on the same candidates sequentially. I think Fox is cause and bubble is the effect, and not vice versa.
Murdoch tweeted readers to watch Santorum in Iowa. It was no surprise his numbers went through the roof. Romney can't compete with Fox News. He's stuck at 25%. Paul has made it to 20%. The rest belongs to Murdoch.