Perry radio ad targets Santorum's earmarks as senator

Rick Perry's new radio ad attacks Rick Santorum, reflecting a growing consensus that Santorum is the front-runner for the support of the large conservative, Christian voting bloc.

Perry's ad, in a humorous game-show style, rips Santorum on a range of earmarks he supported. "Santorum voted for the Bridge to Nowhere and a highway bill full of pork ... Santorum grabbed for a billion in earmarks — until voters kicked him out of office in a landslide."

The ad then plays a quote from Santorum. "I have had a lot of earmarks," he says. "In fact, I'm very proud of all the earmarks I've put in bills."

Santorum's numbers have jumped in recent Iowa polls, capped off by a third-place showing in the latest poll of the state. He took 16 percent support behind Mitt Romney and Ron Paul in a poll released Wednesday by CNN and Time magazine.

Nick Ryan, a former Santorum advisor who is heading an outside group backing him, pushed back against the ad, pointing out that Perry's administration also sought earmarks and ripping his campaign.

"Rick Perry has spent this entire race trying to find a message and can't figure it out," said Ryan. "Attack Newt. Attack Mitt. Attack Santorum. Unfortunately, its desperation time for Rick Perry. Gov. Perry's own words probably sum up this hypocritical attack and are a narrative for his entire campaign: 'Oops.'"

Santorum, Perry, Michele Bachmann and Newt Gingrich are competing for the same pool of voters. Self-identified evangelical Christians make up more than 60 percent of Iowa GOP caucus-goers in most years, and after a series of endorsements from prominent pastors, Santorum has shown some strong momentum with that group.

If he finishes ahead of Perry, that could spell the end of the Texas governor's campaign.

Listen to the ad:

This post was updated at 3:22 p.m.