BURBANK, Calif. – Seated on Jay Leno's couch for the first time since announcing his second presidential bid, Republican frontrunner Mitt Romney faced a wide-ranging interview on Tuesday that covered everything from policy questions on Afghanistan and healthcare to jokes about Rick Santorum and pornography.

"Did you ever think we’d be talking about porn, with all the other things in this election?" Leno asked Romney early in the interview's first segment

"I didn’t know we were talking about porn," Romney said.

"We’re not; Rick Santorum is talking about porn, you and I were talking about porn backstage," Leno responded, in a quip that may have made Ann Romney, who watched her husband's appearance from backstage, blush.

The jab at Santorum wasn't the only mention of Romney's primary competition. In his opening monologue, Leno joked about wanting to have Santorum on The Tonight Show, but that Santorum, who on Sunday cursed at a New York Times reporter, "works too dirty." 

Romney played off Santorum's testy Sunday exchange with the reporter and battles with the press with a joke of his own. Leno would say the names of potential candidates for vice president, and Romney would reply with one word.

When Leno said Nikki Haley, Romney replied, “energetic.” Donald Trump – “huge.” When it came to Santorum, Romney deadpanned. “Press secretary,” he said.

Romney and Leno play vice presidential word association

Earlier, Romney said Santorum deserved "a little bit of slack" for the outburst, explaining that as a candidate for president you are "on all the time," and seemed to suggest he might even consider his rival for a spot on the ticket - a position Santorum indicated he would consider in a recent interview - should Romney become the nominee.

"In this case Rick Santorum is a good guy; he’s running a good campaign. We have some differences in background and differences on some issues but basically a good guy and, you know, 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 chuckled. "I’d rather be the president. Let him be the vice president."

But the interview, which stretched across a commercial break, and for which Romney wore a full suit, was not all fun and games. After the break, Leno pressed Romney on healthcare, Afghanistan and United States relations with Russia.

On health care, Leno pushed Romney to explain what he would offer Americans with pre-existing medical conditions so that they might retain their coverage, perhaps the most popular provision of the president's healthcare law. 

"People with pre-existing conditions, as long as they have been insured before, they are going to be able to continue to have insurance," Romney said, describing his vision for health care if the Affordable Care Act were to be struck down or repealed.

"Suppose they haven't been insured," Leno countered.

"If they are 45 years old and they show up and say I want insurance because I have heart disease, it's like, ‘Hey guys. We can't play the game like that. You've got to get insurance when you are well and then if you get ill, you are going to be covered,’" Romney responded.

But when Leno pushed back, telling Romney he had friends who had worked in the auto industry who had never had insurance before and now were able to get coverage, Romney seemed to soften his stance somewhat.

"We'll look at a circumstance where someone is ill and hasn't been insured so far, but people who have the chance to be insured – if you are working in the auto business for instance, the companies carry insurance, they insure their employees, you look at the circumstances that exist – but people who have done their best to get insured are going to be able to be covered," Romney said. "But you don't want everyone saying, ‘I am going to sit back until I get sick and then go buy insurance.’ That doesn't make sense. But you get defined rules and get people in who are playing by the rules."

Asked about Afghanistan, Romney repeated his claim that announcing a withdrawal date for U.S. forces was a "mistake." In a follow-up question about whether the case of Robert Bales, the man allegedly killed 17 Afghans, Romney suggested that America's forces were stretched too thin. He also doubled down on his call for adding 100,000 troops to the U.S. military.

Leno also pressed Romney on his comments yesterday that Russia was the country’s greatest "geopolitical foe." He read Romney a quote from the current Russian president, Dmitry Medvedev, suggesting that Romney was stuck in the past. Leno asked Romney if the Russians, who have American fast food, “love cars” and “wear fancy clothes” weren’t more like Americans than “our enemies.”

"The Russian people, certainly, are people like us, but you have Vladimir Putin and Mr. Medvedev and they're continuing to support Iran and to keep us from putting in place crippling sanctions against Iran,” Romney said. “They continue to support Assad, Bashir Assad in Syria. They continue to support people like Chavez and Castro. They basically stand up for the world's worst actors, and when America tries to put pressure on those actors with sanctions or other UN actions, Russia always stands up for what I would consider to be the world's worst leaders."