Influential Iowa social conservative leader Bob Vander Plaats has, depending on who you ask, either the ability to propel his chosen Republican presidential candidate to a caucus victory or the ability to latch onto the winning campaign. So it was a big deal, if not surprising, when Vander Plaats endorsed Ted Cruz earlier this month, snubbing his 2008 and 2012 picks Mike Huckabee and Rick Santorum, respectively.

In an interview with conservative Iowa radio host Simon Conway yesterday, Santorum said that Vander Plaats, who heads the group The Family Leader, was “settling” with his pick of Cruz, citing Cruz’s efforts to allow states to ban same-sex marriage rather than controlling marriage on the federal level.

“Look, I understand it,” Santorum said. “Ted’s a fine guy and has really been a scrapper in Washington. I think what Mike and I both feel is that when it comes to the issues that are near and dear to The Family Leader, the family issues, marriage in particular, I think we need a stronger voice, a more principled voice that understands there’s a higher law there that we have to abide by and just because a state wants to do something doesn’t mean a state should be able to.”

This prompted Conway and Santorum to launch into an extended debate about the role of government in marriage, which Conway argued the government should have nothing to do with at all.

Santorum disagreed, saying that the government has a responsibility to ensure the “continuity” of culture, citing low birth rates among native Europeans — the unspoken subtext of which is that low birth rates necessitate greater immigration. “If you look at Europe … they’re decrying the fact that Europe is barren,” he said, “they’re not having children, and the people who are having children are not Europeans, or native Europeans, so you’ve got some really big problems and it’s beginning to occur in this country.”

He added that laws governing marriage also serve to “encourage people to behave the right way” when “fidelity, monogamy are not a natural thing” but “are learned behaviors.”