Romney is so foolish here on so many levels it is hard to list them all. The main issue is that he is spitting on the people he wants to support him. A close second is the fact that while Gingrich hits back he also ANSWERS the question.
Romney's entire campaign is the liberal GOP establishment trying to stick it to the GOP base, rubbing our face in their excrement. That's why, right before New Hampshire, he trotted out John McCain: "See, I'm going to win this thing with the help of the same non-GOP voters who gave you McCain, and you're just going to have to deal with it whether you like me or not. Shut up and sit down!"