Dan Amira nods:
There's no telling what horrible things could befall Romney in the coming months. Maybe some damning tax revelations will leak out. Maybe a former Bain executive will turn up and admit that he and Romney used to smoke cigars filled with $100 bills as they laughed maniacally about the companies they'd looted. Maybe Romney will be caught on camera insisting that corporations are more personlike than fetuses. You can never know. If a major gaffe should damage Romney, it's not going to help Gingrich unless he's still in the race.
Newt predicts that the primary will go on for another six or eight months, "unless Romney drops out earlier."