It's All About Newt

(AP Photo/Evan Vucci)

Republican presidential candidate, former House Speaker Newt Gingrich, accompanied by his wife Callista, speaks at Peachtree Academy, Wednesday, Feb. 29, 2012, in Covington, Ga.

For all the Sturm und Drang of the last few weeks, Mitt Romney will begin March in the same way that he began February—as the front-runner for the Republican presidential nomination. Rick Santorum is at his heels as the latest avatar of the conservative movement, Ron Paul is the libertarian gadfly of the race, and Newt Gingrich has receded to the background as a virtual non-factor. Except that he isn’t.

Unlike Paul, who pulls from the younger ranks of GOP voters, Gingrich draws his remaining strength from the same Tea Party voters who delivered a strong showing for Santorum in Michigan and might give him a win in Ohio next week. The exit polls suggest as much. Gingrich fared best among groups Santorum won: voters who never attended college, union members, households with union members, very conservative voters, evangelical Protestants, and people who strongly support the Tea Party. If Gingrich weren’t in the race—or if his campaign weren’t propped up by regular infusions of outside cash—there’s a fair chance that some of those voters would have gone to the former Pennsylvania senator. In which case, Santorum would have captured a win in the Great Lakes state, and the race—or at least, its narrative—would be in a different place.

All of this is to say that his presence will play a big part on Super Tuesday. As of today, Gingrich has a lead in one place—his home state of Georgia. There, he is ahead in the field by an average of nine points, and if he wins Georgia next week, he will have deprived Santorum of a likely and important pickup; Georgia is large, diverse, and increasingly cosmopolitan thanks to the explosive growth of Atlanta over the last decade. If Santorum wins in Georgia and Ohio—where he benefits from the state’s large population of conservative, blue-collar workers—it would generate the momentum he needs to continue the race.

Adding to that is the possibility of wins in Tennessee and Oklahoma, which fit the Santorum base of religious conservatives and downscale whites. In a world where Gingrich has left the race, there’s no doubt that Santorum would leave Super Tuesday with solid wins and a renewed shot at dislodging Mitt Romney.

Alternatively, Romney needs the former House speaker to stay in the race; as long as Santorum can't build the momentum to overtake Romney, the former Massachusetts governor maintains the space he needs to move to the center in a general election. But a stronger Santorum puts pressure on Romney to shore up his bona fides and convince conservatives that he remains their best option for winning the election and rolling back Barack Obama's liberalism. More important, a stronger Santorum lifts the bar for conservative orthodoxy; Romney would have to go further to the right—and show even greater hostility on issues like contraception or immigration—in order to maintain his position with conservative voters. In which case, flipping back to the center becomes incredibly difficult, if not impossible. This might satisfy the Republican base—which doesn't trust Romney in the first place—but it would be a disaster for his general-election campaign.