Rick Santorum trails in the GOP's delegate hunt, with approximately 180 delegates to Romney's 420 as each man races toward the 1,144 needed to clinch the nomination.

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any Rick Santorum supporters are urging Newt Gingrich to drop out of the Republican presidential race, which would leave Santorum as the sole conservative in what would essentially be a one-on-one race against frontrunner Mitt Romney. Many commentators agree that Gingrich's departure is Santorum's only real hope for toppling Romney, who is racking up a commanding lead in delegates, states won, and raw votes as his rivals compete for the same pool of anybody-but-Romney voters. But would Gingrich's withdrawal really give Santorum a shot at winning the nomination?

It's too late: If Newt had dropped out after his big loss in Florida, "the dynamic of the Republican contest could be drastically different today," says Matthew Jaffe at ABC News. Santorum would have won Ohio, Georgia, and Alaska —and would have benefited greatly from the resulting momentum. But "playing the game of 'what might have been?' is a pointless exercise." Thanks to Gingrich's frustrating persistence, "Romney now has a huge — seemingly insurmountable — lead."
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Newt's exit would help, but Santorum needs more: The ex-senator's delegate deficit isn't "mathematically insurmountable," but he can't realistically win without a couple big changes in the race, like Gingrich quitting, says Nate Silver at The New York Times. Data suggests that Santorum would pick up 57 percent of Gingrich voters, while Romney would take 27 percent — "a necessary but not sufficient" boost for Santorum. To win, "he'll need to find some further means by which he can eat into Mr. Romney's coalition," and fast.
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Santorum can still win — even if Newt stays in: "Delegate-wise, this contest is still early in the second quarter — or, if you prefer, in the bottom of the third inning," says Jeffrey H. Anderson at The Weekly Standard. That leaves plenty of time for Santorum to turn this around. And it wouldn't take much. No matter what Newt does, if Santorum wins a little bit more and Romney loses a little bit more, the Pennsylvanian could plausibly "work himself into a delegate tie with, or even a lead over, Romney, by the end of the contest."
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