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The pro-Rick Santorum super PAC is out with its first negative ad against the candidate's GOP opponents. It starts running today in the upcoming caucus state of Minnesota.

The Red, White and Blue Fund's latest television commercial, called "The Only One," will air in the Minneapolis market comparing Mitt Romney and Newt Gingrich to President Obama. The state's caucuses are Feb. 7.

The 30-second spot shows images of Obama, Romney and Gingrich while the announcer says, "They're not so different."

"Supporting big government that strangles our nation's ability to create jobs. Bailouts. Government-run health care," the voiceover reads before asking, "Who can we trust?"

The ad goes on to say that Santorum is the "only proven conservative," a theme repeated in almost all the ads from the independend super PAC and Santorum campaign's own ads.

The super PAC's previous ads touted Santorum's conservative credentials and family life or contrasted his record with Obama's, but this is the first time the group has specifically zeroed in on Romney and Gingrich, instead of just showing images of his opponents.

The group did not release information regarding the size of the ad buy.

The Red, White and Blue Fund said it decided to go up on the air in Minnesota because polling shows Gingrich up and Romney down in the state and if Gingrich implodes, they believe Santorum has a good shot at the state. He had a campaign event there Sunday that drew such a large crowd they had to move locations.

Watch the ad here.

On Wednesday, the fund launched an ad in Missouri, which also votes Feb. 7, but in non-binding caucuses.

"Obama's reckless agenda must be stopped. And there's only one principled candidate with the courage to do it. Rick Santorum, Father. Husband. A champion for life. The leader with a bold plan to restore America's greatness," the Missouri ad reads.

The ad called "Trust" ends with the same theme, "Proven conservative."

Watch the ad here.