Romney jokes about Santorum on ‘The Tonight Show’

Mitt Romney joked in an interview with "Tonight Show" host Jay Leno that he wouldn't mind picking David Letterman as his vice presidential running mate. But he wasn't nearly as kind to Rick Santorum, using the phrase "press secretary" when asked to describe his GOP rival during a word association game.

Still, in an appearance that ranged from humorous to serious, Romney didn't quite rule out Santorum as a potential running mate. Asked about the former Pennsylvania senator's comment Monday that he'd be willing to serve as Romney's VP, the former Massachusetts governor told Leno that he's "happy" that Santorum made the suggestion.

"I'm happy with him saying he'd like to be part of an administration with me, nothing wrong with that, if he's the VP that's better," Romney said. "I'd rather be the president, let him be the vice president."

But Romney played coy when asked who exactly would be on his short list for VP. Leno then coaxed Romney into playing a game where he uttered the first word that came to mind as he named possible running mates.

Asked about New Jersey Gov. Chris Christie, Romney replied, "Indomitable."

Romney described Florida Sen. Marco Rubio as "the American dream," Rep. Paul Ryan as "creative," South Carolina Gov. Nikki Haley as "energetic" and real estate tycoon Donald Trump as "huge."

Asked about Santorum, Romney immediately replied "press secretary"—no doubt a reference to an incident over the weekend in which the ex-senator cursed at a New York Times reporter.

Still, Romney had praise for his opponent, calling him a "good guy who has run a good campaign."

But the interview wasn't all fun and games. Under intense questioning from Leno, Romney defended his pledge to repeal President Obama's health care plan but—as he has at previous campaign stops—insisted he would keep a provision that requires insurance companies to offer coverage to people with pre-existing conditions.

And he defended his criticism of Obama's relationship with Russia, accusing the Kremlin of constantly siding with "the world's worst leaders."

At one point, Leno quizzed Romney on Santorum's pledge to crack down on pornography if he were elected president.

"Did you ever think we'd be talking about porn, with all the other things in this election?" Leno asked the candidate.

"I didn't know we were talking about porn," Romney replied.

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