Restore Our Future, an outside group backing Mitt Romney, is taking its first shot at Rick Santorum. The group is running ads in South Carolina and Florida criticizing Santorum for supporting earmarks, part of multi-million dollar ad buys running in the states.

Even after Santorum almost won Iowa, the group kept its focus on Newt Gingrich. But now it seems to see him as the biggest threat to Romney.

"Barack Obama knows four facts about Rick Santorum that you don't," the ad's narrator says. "Santorum pushed for billions in wasteful pork — voting for the Bridge to Nowhere, a teapot museum, even an indoor rainforest. Santorum voted to raise the debt limit five times, increasing spending and debt by $3 trillion. He even voted to let convicted felons vote. So how will Rick Santorum beat Obama? Obama knows: He can't."

Romney is the only candidate with the funds to already be running ads in Florida, an expensive state that votes on Jan. 31. The help from Restore Our Future, a group run by former Romney aides, is helping to push his message there.

Rick Perry also criticized Santorum for earmarks. He ran a Web ad before the Iowa caucuses calling the former senator a "porker's best friend."

Watch the ad: