Mitt Romney has claimed credit for preventing Massachusetts from “becoming the Las Vegas of gay marriage.”

Romney made the claim on Friday during a speech to the annual Conservative Political Action Conference (CPAC) in Washington D.C.

“Now, you may recall as well that during my term in office, our conservative values also came under attack. Less than a year after I took office, the [Massachusetts] Supreme Court inexplicably found a right to same-sex marriage in the constitution written by John Adams,” Romney told a receptive audience. “I presume he'd be surprised. I fought to have a stay on that decision, then pushed for a marriage amendment to our constitution – We lost by only one vote in the Legislature. And I successfully prohibited out-of-state couples from coming to our state to get married and then going home. On my watch, we fought hard and prevented Massachusetts from becoming the Las Vegas of gay marriage.”

(Relate: Mitt Romney blasts Prop 8 ruling.)

Romney has previously been attacked by Rick Santorum and Michele Bachmann with claims that he advanced gay marriage during his tenure as Massachusetts governor.

“He personally, as governor, issued gay marriage licenses,” Santorum asserted during a GOP debate in Iowa.

A surprised Romney responded by saying he was powerless to stop the court: “The idea that somehow that was up to me to make a choice as to whether we had it or not was a little unusual.”

At CPAC, Romney also said that as president he would defend the Defense of Marriage Act (DOMA), which bars federal agencies from recognizing the legal marriages of gay couples from states such as Massachusetts.

“When I am president, I will defend the Defense of Marriage Act,” Romney said. “I will fight for an amendment to our constitution that defines marriage as a relationship between a man and a woman.” (The video is embedded in the right panel of this page. Visit our video library for more videos.)