Gene J. Puskar/AP Photo

ABC News' Michael Falcone reports:

Former Pennsylvania Sen. Arlen Specter left Capitol Hill more than a year ago, but Mitt Romney's campaign is working hard to give the party-switching ex-lawmaker a political revival of sorts.

The Romney campaign released a new web video on Friday highlighting the alliance between Specter and Rick Santorum when the two were colleagues in the U.S. Senate.

"Rick Santorum supported Specter over conservative candidates - twice," the video's narrator says. "Santorum and Specter voted for liberal Circuit Judge Sonia Sotomayor. Santorum and Specter both sided with big labor against right to work."

But the most damning charge is the one that Romney, himself, made at Wednesday night's presidential debate in Arizona: That Santorum's continued support of Specter helped deliver the deciding vote for President Obama's health care plan.

(Santorum endorsed Specter in his 2004 Senate race and again, six years later, in a Republican primary against the more conservative candidate, Pat Toomey.)

The video juxtaposes images of Specter with President Obama and, separately, with Santorum. It also includes a clip of a 2004 campaign ad paid for by Specter's Senate campaign featuring Santorum's public support.

"I'm proud to endorse Arlen Specter," Santorum said in the old ad.

Romney raised the ties between the two Pennsylvania politicians at the debate, chastising his rival: "If you had not supported him, if we had said 'no' to Arlen Specter, we would not have ObamaCare," Romney said. "So don't look at me. Take a look in the mirror."

At the debate, Santorum suggested he cut a deal with Specter to support him in exchange for Specter's support of President George W. Bush's judicial nominees.

Not so, Specter said in an interview on Thursday with ABC News. He denied striking such a deal with Santorum and expressed surprise that he had become an issue in this year's Republican nominating contest.

"There are a lot more important things to discuss than Arlen Specter," he said.

But the Romney campaign is determined to keep the former senator front and center.

"If Rick Santorum couldn't say no to liberal Arlen Specter, can you really trust him to change Washington?" the Romney web video concludes.