The religion of Mitt Romney, the first Mormon presidential nominee, has been a rarely discussed subtext of his campaign. While Romney has never hid his beliefs he’s also been criticized for failing to open up about a religion unfamiliar to so many Americans.

The issue is unlikely to be answered with a newly emerging video of a visibly upset Romney sparring with a conservative radio host.

The video, taken in 2007, has suddenly gone viral as Election Day approaches. As much as Romney’s faith has been questioned, he’s also struggled to field attacks on his almost robotic public image. That was nowhere on display during Romney’s heated argument with Jan Mickelson, a right-wing broadcaster out of Iowa.

Mickelson’s questions aren’t shown, but he apparently pressed the candidate (who would eventually lose to John McCain during the 2008 Republican primaries) on his religion. The theological battle also had Romney taking aim at implications he felt Mickelson was making.

“I’m not running as a Mormon,” Romney said in the video. “And I get a little tired of coming on a show like yours and having it be all about Mormons."

The Republican became increasingly flustered as the interview wore on, at one point standing up and pacing throughout the room.

“Let me once again say, I understand my faith better than you do,” Romney said. “You don’t believe that, do you?”

The discussion centered mostly around abortion, where Mickelson repeatedly said he agreed with Romney. Conservatives have questioned Romney's commitment on the issue, citing his earlier pro-choice statements.

“I was beaten up in Boston because I pointed out, time and again that I encouraged girls not to get abortions, that I told them to have adoptions,” Romney said, referring to his time as a church leader. “I have not done anything that in any way violates the principles of my church in that regard.”

While the video may have surfaced too close to Nov. 6 to make an impact at the polls,  Politico reported Romney did explain himself to Katie Couric, saying a “TV or radio talk show host the other day in Iowa … began drilling me about my faith.”

“I became intense in confronting what he had said,” Romney said, according to a transcript from CBS. “And we went back and forth. Unbeknownst to me, he had a hidden camera on the console. So this then popped up on the Internet - as our exchange. And I was intense. I wasn’t angry. I wasn’t out of control. But I was intense.”