Rick Santorum Unveils Michigan Ad Accusing Mitt Romney of Mud-Slinging

(Image Credit: AP Photo)

ABC News' Shushannah Walshe and Michael Falcone report:

UPDATED BOISE, Idaho - The Santorum campaign hit the Michigan television airwaves today with a new 30-second ad rebutting some of the negative ads a pro-Romney super PAC is running in the former Massachusetts governor's home state.

Unlike two positive spots the Rick Santorum campaign unveiled earlier this week, this one features a Mitt Romney look-alike in a crisp white shirt and cufflinks carrying an automatic weapon trying to shoot at a cardboard cut-out of Santorum with mud pellets.

The ad, with its fumbling Romney impersonator, is meant to be partly humorous, but there's a serious message, too.

"Mitt Romney's negative attack machine is back, on full throttle. This time, Romney's firing his mud at Rick Santorum," the ad's narrator says. "Romney and his super PAC have spent a staggering 20 million attacking fellow Republicans. Why? Because Romney's trying to hide from his big-government 'Romneycare,' and his support for job-killing cap-and-trade. And, in the end, Mitt Romney's ugly attacks are going to backfire."

During the ad, the Romney doppelganger runs through an abandoned building taking aim at the Santorum cut-out. At the end, the gun backfires on "Romney" and mud splatters all over his white shirt.

A Republican media buying source said the campaign has purchased nearly $41,000 to reserve air time in the state so far, a figure that Santorum aides would not confirm. It is not clear how that amount will be divided among the three ads.

Santorum is accusing Romney of mudslinging at the same time that he has been doing his fair share of attacking. The former Pennsylvania senator has been contrasting his record with Romney's on the stump all week.

"Sen. Santorum is a typical politician talking out of both sides of his mouth," Romney spokeswoman Andrea Saul said in a statement responding to Santorum's Michigan ad. "He has been attacking Mitt Romney in his public statements and in television ads for weeks, not vice versa."

The Romney campaign pointed out that they have not run a single negative television ad against Santorum, but the campaign has been holding their opponent's feet to the fire in other ways.

On Wednesday, for example, Romney surrogates held a conference call to discuss what they called "Rick Santorum's record of increasing government spending and earmarks." A pro-Romeny super PAC, Restore Our Future, has been sounding similar themes in an attack ad running in Michigan and other states. And Romney, himself, criticized Santorum and fellow candidate Newt Gingrich by name recently as Washington insiders.