Ryan Anderson, a fellow at the conservative Heritage Foundation and the author of What Is Marriage?, claims that laws prohibiting gay marriage are constitutional.

Anderson made his comments during an appearance on cabler CBN's The 700 Club.

When asked his opinion on two cases related to the issue before the Supreme Court, Anderson said the court should uphold the Defense of Marriage Act (DOMA) and California's Proposition 8. DOMA is the 1996 law which prevents the federal government from recognizing the legal marriages of gay and lesbian couples, while Proposition 8 is the 2008 voter-approved constitutional amendment which reversed a California Supreme Court ruling legalizing marriage equality.

“The law here is pretty clear,” Anderson said. “The Supreme Court should uphold both Proposition 8 and Defense of Marriage Act. Our constitution does not require the redefinition of marriage. Marriage laws that reflect the truth about what marriage is are wholly constitutional. And citizens have the authority to vote about what marriage is. Unelected judges should not be redefining marriage.”

Anderson also claimed that marriage equality would lead to plural marriages.

“Because if marriage is just about a community of love, you know whatever consenting adults choose to love, that can come in as many sizes and shapes as consent comes in. So, if you say there's a fundamental right to marry the person you love, why not the people you love? If justice demands same-sex marriage for the same-sex couple, why not the same-sex throuple? A throuple is a three-person couple.” (The video is embedded on this page. Visit our video library for more videos.)

Earlier, Anderson got into a heated debated with money guru Suze Orman during an appearance on CNN's Piers Morgan Tonight.

(Related: Suze Orman, Piers Morgan dismiss arguments of gay marriage foe Ryan Anderson.)