Granted South Carolina isn't until Jan. 21 and things could change but Romney will have a great deal of momentum coming out of New Hampshire even if he is expected to win there.
The nomination process is spread out this time. It will take a little while to win enough delegates to get the nomination. This could and the emphasis is the word could allow some other candidate to catch on and challenge Romney. But who might that be. Of those left the only one that hasn't shot to the top and then dropped like a stone is Santorum. The problem Santorum has is that he doesn't have enough money, at least right now, and little if no organization. It also seems he's running into a little bit of trouble in New Hampshire with his social positions:
On Friday, he was aggressively heckled at a wild campaign stop at a restaurant. The event was forced into the parking lot after a fire marshal deemed the building too crowded. As Santorum spoke, he was interrupted periodically by shouts.
“What about equality for the gays?” one man shouted and, after Santorum opened with a request for respect, the man continued, “How much respect do you have for gay people, Rick?”
But the main thing that has to happen to stop the Romney bandwagon is that someone has to win. And win pretty big I'd say. I just don't see where that happens.