He continues to argue vigorously against the idea that Romney is the most electable contender in the race. "What chance do we have in the general election if, with his overwhelming financial advantage, he can't deal a knockout blow?" Santorum argued against Romney this week.

Romney pushed back on Fox News on Monday, saying he’s "closing the deal, state by state, delegate by delegate” and his campaign is “pretty pleased with the progress we're making.”

Santorum leads Romney 34 percent to 30 nationally in the new CBS/New York Times poll, conducted between March 7 — “Super Tuesday” in 10 states — and March 11. Santorum’s lead falls within the poll’s margin of error.

Newt Gingrich and Ron Paul trail with 13 and 8 percent support, respectively.

Santorum has a much stronger lead among evangelical and Tea Party voters, according to the poll.