Facing arguments that Mitt Romney's delegate lead is virtually unbeatable, Rick Santorum on Sunday made his own case as to how the delegate math could work in his favor.

Romney currently leads with 454 delegates and Santorum follows with 217. Newt Gingrich is well behind with 107 delegates while Ron Paul trails with 47. To secure the nomination, a candidate needs 1,144 delegates in total.

"This isn't a mathematical formula," Santorum said. "This race has a tremendous amount of dynamics. And you know we've got a lot of states coming up that are great -- that are going to be great states for us, states like Pennsylvania where you know we got 72 delegates that we should win, if not all of them, the vast majority of them. And Texas -- last poll in Texas had me up 30 points."

Santorum noted that delegate portions remain in flux even in states that have already voted -- like Iowa.

"You know we barely won Iowa by 34 votes but they had their conventions yesterday, we're going to win the vast majority of delegates in the state of Iowa. But nobody has that in their count. They have us winning by one vote," he said. "That's not going to be the case when the delegates from these caucuses are actually elected."

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He noted that in other cases, delegates currently assigned to one candidate are actually uncommitted, saying that "these numbers are going to change dramatically."

"And you have a whole bunch of super delegates. Again, Governor Romney has secured several of them, but they're not bound with their -- with their commitment," Santorum said. Super delegates are party leaders or elected officials who are free to support any candidate for the nomination, regardless of the outcome of their states' primary or caucus vote.

"These are the kinds of things that ... can change as the dynamic of this race changes as we go on," Santorum said.

Although Santorum continued to say he wants a head-to-head matchup with Romney, he declined again on Sunday to ask Gingrich to leave the race.

"I'm not going to tell people to get in or out of this race," he said. "I didn't ask Speaker Gingrich to get in and I'm not going to ask him to get out."

Santorum was asked about the mathematical arguments against him during an appearance on NBC's "Meet the Press."