CEDAR RAPIDS — While more than 50 protesters gathered outside, conservative leader Bob Vander Plaats’ appearance went mostly uninterrupted on Tuesday night until gay rights supporters engaged the Republican politician in a back-and-forth about the separation of church and state.

Vander Plaats, a three-time gubernatorial race loser, visited Godfather’s Pizza, located at 3647 First Ave SE, on a 99 county tour for the Family Leader, a Christian conservative group he heads.

Vander Plaats urged the crowd of about 75 to keep up the momentum from last November’s elections when Iowa voters ousted three Iowa Supreme Court justices over a controversial ruling legalizing gay marriage and gave Republicans control of the Iowa House.

“Is this going to be a movement to really take this country back for faith, family, and freedom?” Vander Plaats said. He added that maintaining one man, one woman marriage is central to that movement. “Strong marriages lead to strong families which lead to a strong society.”

Vander Plaats repeatedly cited the Bible to support his position and called the government “an institution of God.” A handful of audience members took issue with that, pushing Vander Plaats on what they called a mixing of church and state.

Vander Plaats responded by saying the erosion of traditional marriage could lead to the legalization of polygamy or incest. The scuffle between Vander Plaats and the audience members persisted for about 10 minutes until Vander Plaats had an aid conclude the event.

Several hundred gay marriage opponents gathered in Des Moines earlier on Tuesday, urging lawmakers to advance legislation which would amend the state’s constitution to ban same-sex unions. That bill has cleared the Republican House but Senate Majority Leader Mike Gronstal, D-Council Bluffs, has vowed to block it in the Senate.

In addition to the constitutional amendment, Vander Plaats has called for the resignations of the four remaining Supreme Court justices who signed onto the decision legalizing gay marriage.

“Bob Vander Plaats is trying to impose a religious agenda and we support the separation church and state,” Charles Crawley said during a rally before the event. Crawley is an organizer with Faith in Iowa, a group that opposes removing judges based on the court’s gay marriage decision. “People across Iowa have awoken to what’s going on and this won’t happen again.”

Crawley and the other protesters waved signs and chanted “Hey, hey, BVP, why can’t you just let it be?” before and during the Family Leader’s event. Vander Plaats said that crowd was probably the biggest group of demonstrators he has encountered on his tour of the state, but he isn’t fazed by the dissent.

“Some people say this is an extreme agenda,” he said. “This is about the foundation of society — one man, one woman marriage — and the constitution of Iowa and the United States. That’s not extreme.”