Republicans who despise Newt Gingrich hold one of two conflicting theories about him: Either he's a dangerous maniac who will collapse under his own weight; or he's a dangerous maniac who must be stopped.
Among moderate and Estabishment Republicans, the case for complacency is a compelling one: Gingrich, this argument goes, wears poorly. The less voters hear of him, the more they like him -- this was literally the case in early polling -- and the higher he rises, the faster he falls. His success reminds voters of his past and his personality, and they reject him. There is, by this theory, a mathematical equation that will stop Gingrich from being the nominee, and -- apologies to Nate Silver -- his probability of victory is always zero.
The other theory is embraced primarily by Gingrich's supporters. He's not winning despite his combative, undisciplined personality; he's winning because he's Newt. Voters embrace the large, flawed, complex, and visibly intelligent candidate one they fear lacks depth. Gingrich's powerful message, as Alex Castellanos recently wrote is that his "opponents are fine but you know they are not the big leader you need."
Romney's staff projects a belief in the former theory. McKay Coppins recently talked to a top aide:
Asked whether Romney's collapse in the polls is forcing Romney's campaign to consult its own mortality, the aide laughed.
"Oh God, no," he said. "I mean, to face Newt Gingrich?"
The last two days have pretty fully undercut that blase pose. If you're not afraid of someone, you don't try to tear his face off.