“If he finishes second, I would consider that a win because next he goes to Nevada, Maine and we’ve got Super Tuesday coming up and there’s a very important state that’s on Super Tuesday, Georgia, and so I happen to believe that if he comes in second he keeps on going," Cain said.

A Washington Post review last week estimated that the Romney campaign and associated political action committees had spent nearly twice as much as Gingrich and his allies in the state, and that nearly 80 percent of those advertisements were critical of Gingrich. Money matters in the Sunshine State, by far the most diverse and expensive of the early voting contests.

But, as Romney himself pointed out Monday morning, he's also bested Gingrich in the format that traditionally favors the former House Speaker — the GOP debates.

"I think if you were to go back and look where the sentiment changed, it was with the debates," Romney said on NBC.

Cain endorsed Gingrich at an event in Florida Saturday night, despite Cain having previously said that he would not choose a favorite in the GOP primary. The pair will campaign together in Tampa on Monday.