Updated

Former Senator Rick Santorum (R) says if he is elected, he will take judicial appointments very seriously and he'll "have a litmus test that they should follow the Constitution."

"There will be no one stronger on judges than I am," said Santorum Sunday on Fox News. He touted his work in Congress to help push President George W. Bush's judicial appointments through as evidence.

"We took the battle to the Democrats when they were going to shut them down and they had in the past. When I was in that leadership, I said, we're not going to do that anymore. We're going to have all night filibusters, we're going to try to break them (Democrats)," added Santorum.

Many have criticized Santorum for his endorsement of then moderate Republican Senator Arlen Specter. But Santorum says that was a quid-quo-deal. Santorum said he agreed to endorse Specter in exchange for Specter voting in favor of President George W. Bush's conservative judicial nominees in 2004.

Santorum's endorsement helped Specter beat out Pat Toomey, who was later elected in 2010.

Santorum also took jabs at his rival, Mitt Romney over his past judicial appointments.

"Governor Romney appointed dozens of left wing, radical judges, liberal activist judges in Massachusetts," said Santorum.