Scott Conroy bucks conventional thinking:
Gingrich’s continued presence in the campaign may be the only way that Romney can be denied the 1,144 delegates he needs to lock it up. If Gingrich were to drop out, various polls show that Santorum would garner the majority of the former speaker’s support. Nonetheless, in a two-man race with Romney, the math is more difficult for Santorum, not less. Romney figures to win enough of the delegates Gingrich otherwise would have taken to prevent Santorum from overtaking him.
Gingrich is making a version of this argument himself. Harry Enten's calculations don't agree:
In states that are proportional (like North Carolina and Texas), Gingrich getting out would makes no real impact on Romney's delegate total (and may actually help him a little). In states like Arkansas, California, Illinois and Wisconsin, where there is some version of winner-take-all on the state or congressional district level, Gingrich is helping Romney. But with Gingrich out of the picture, Romney probably gets 50-100 delegates fewer than he does with Gingrich in the race. I'm not saying this will deny Romney a first-ballot victory, but it would make it more interesting.
The Dish 