The fiscally conservative Club for Growth released a statement blasting Rick Santorum for his support of then-Republican Sen. Arlen Specter's (Pa.) reelection bid in 2004 and defending Mitt Romney for hitting Santorum on the issue.

"Gov. Romney is right: Arlen Specter was the 60th vote for ObamaCare and Rick Santorum helped put him there," said Club for Growth President Chris Chocola. "Rick Santorum jettisoned conservative principles to support Arlen Specter when the Club for Growth PAC and much of the conservative movement was supporting Pat Toomey. Now he is pretending that his politically expedient support for Specter was based on principle when everyone in the Senate knew that Arlen Specter was a liberal, big-government Republican."

Santorum went to bat for Specter in his primary, and has argued since that he did so because Specter promised him he would help push through conservative judges.

Toomey narrowly lost that primary, then went on to head the Club for Growth before winning his Senate seat in 2010 after Specter defected to the Democratic Party, then lost in the primary.

Chocola and Toomey are close: While Toomey ran the Club he brought Chocola in to help, and picked him as his successor when he decided to run for the Senate.

"Elections have consequences, and if Rick Santorum wants to lamely take credit for Specter's judicial votes, then Santorum should both take responsibility and apologize for enabling Specter's critical role in the passage of ObamaCare.”

While Chocola and the Club have not endorsed in the race, they have been critical of Santorum at other times. But Chocola has also ripped Romney, telling The Hill on Wednesday that the former Massachusetts governor talks "in the language of the left" on tax policy and that his new tax plan is "not inspiring."