Des Moines, Iowa — Social conservative candidate Rick Santorum is pulling ahead in Iowa polls just a day before the Republican caucus, and he's also pulling even more anti-gay rhetoric out of his pocket.

In an interview with NBC, Santorum said not only does he want a constitutional amendment banning gay marriage -- he'd like to un-marry gays and lesbians who have already tied the knot.

"Well, their marriage would be invalid," Santorum said. "If the constitution says 'marriage is this,' then people whose marriages are not consistent with the constitution...I'd love to think that there was another way of doing it."

Santorum pointed out that people in 32 states have voted against allowing gay marriage, even though courts and lawmakers have approved it.

When asked whether "the people" were always right, Santorum said: "Just because public opinion says something, doesn't mean something's right if it's not right."

The Des Moines Register said that in a poll taken Friday, Mitt Romney led with 23 percent and Santorum had 22 percent. That's a big gain for Santorum in just the past week.

The caucuses will be held on Tuesday, Jan. 3.