Rick Santorum Blasts Mitt Romney: He Offers No Vision, Is About 'Serially Tearing Down' Opponents

Rick Santorum is using his newfound momentum in the Republican presidential primary to mount a vigorous defense against frontrunner Mitt Romney.

After an energetic Oklahoma City rally on Thursday, Santorum told reporters that Romney's negative campaign against him masked a scarcity of ideas.

"Governor Romney's campaign has been about serially tearing down but not offering any kind of vision about what he wants to do for this country," Santorum told reporters, according to CNN.

Since Santorum's dominant performance in three GOP contests in Missouri, Minnesota and Colorado on Tuesday night -- the latest wrench in an unpredictable GOP race -- Romney has re-focused his energies on the former Pennsylvania senator, who had faded after (technically) winning the Iowa caucus in January.

Romney surrogates like Tim Pawlenty have gone after Santorum on earmarks, particularly his vote for the notorious "Bridge to Nowhere" project. They have also labeled Santorum as a Washington insider who lacks managerial experience.

Santorum responded on Thursday by accusing his rival of running a race to the bottom.

"This is the gotcha politics of Mitt Romney," he said. "It's not interesting to talk about the issues. He's not interested in talking about the issues. He's interested in trying to pander and make political sauce, when there's real substantive issues about how we're trying to change this government, and he's on the wrong side."

Santorum has also been trying to connect Romney to President Barack Obama on social issues. On Wednesday, he published an op-ed criticizing Romney for saying he believed "in his heart of hearts" that Catholic hospitals should provide emergency contraception to rape victims. That came on the heels of Obama's controversial decision that religious institutions providing health care must cover the cost of birth control, which has caused a furor among conservatives.