Bob Garon, the Vietnam veteran who asked Mitt Romney his thoughts on gay marriage, says Romney “doesn't know about the Constitution.”

Romney approached Garon, 63, on Monday during a campaign stop at Chez Vachon diner in Manchester, New Hampshire.

Garon asked Romney about New Hampshire Republicans' plans to repeal the state's 2-year-old gay marriage law.

“I support repeal of the New Hampshire law. I believe marriage is between a man and a woman. That's my view,” Romney told Garon.

“It's good to know how you feel,” Garon said. “That you do not believe that everyone is entitled to their constitutional rights.”

“No, actually, I think at the time the Constitution was written it was pretty clear that marriage is between a man and a woman,” Romney said. “And I don't believe the Supreme Court has changed that.”

During an appearance on MSNBC's Hardball, Garon said he was surprised by Romney's answer.

“Well, I was very surprised,” Garon said. “First, I'm not a professor of the Constitution. I didn't know he was either. I didn't know that the Constitution made it clear what a marriage was … between a man or a woman. There's nowhere in the Constitution that I can remember that it says anything about that. And here's a man that plans to be in the White House and apparently he doesn't know about the Constitution either. I was dumbfounded. I just don't know where he came up with that kind of information.” (The video is embedded in the right panel of this page. Visit our video library for more videos.)