Self-styled Montana polygamist Nathan Collier poses with his wives Christine (R) and Vicki in this undated handout photo courtesy of Collier. Collier, 46, said his bid to make his marriage to his second wife “legitimate” was influenced by the U.S. Supreme Court decision last week that legalized same-sex marriages in the United States. (Nathan Collier/Handout via Reuters)

The Supreme Court’s decision in June that legalized same-sex marriage across the country has unleashed a renewed debate over polygamy, leaving some to wonder why marriage should be considered between just two persons.

The first legal challenge involving polygamy came last week after a man from Montana said the Supreme Court’s decision inspired him to apply for a marriage license so he can legally marry a second woman. Nathan Collier, who was featured on the reality television show “Sister Wives,” said he will sue the state if it denies him the right to enter into a plural marriage.

“It’s about marriage equality,” Collier told the Associated Press. “You can’t have this without polygamy.” A county civil litigator Kevin Gillen said he was reviewing Montana’s bigamy laws and expected to send a formal response to Collier by this week.

Chief Justice John G. Roberts’s dissenting opinion raised the question of whether the court’s rationale could be used to legalize plural marriage down the road.

“Although the majority randomly inserts the adjective ‘two’ in various places, it offers no reason at all why the two-person element of the core definition of marriage may be preserved while the man-woman element may not,” Roberts wrote. “Indeed, from the standpoint of history and tradition, a leap from opposite-sex marriage to same-sex marriage is much greater than one from a two-person union to plural unions, which have deep roots in some cultures around the world.”

Some are now using Roberts’s arguments to revisit the idea of legalized polygamy.

“It’s time to legalize polygamy,” writer Fredrik Deboer declared on the day of the Supreme Court’s decision, arguing that “the marriage equality movement has been curiously hostile to polygamy, and for a particularly unsatisfying reason: short-term political need.” His essay provoked a series of responses, including one from Brookings Institute’s Jonathan Rauch, who defends gay marriage but not polygamy. “It’s no coincidence that almost no liberal democracy allows polygamy,” Rauch wrote.

Jonathan Turley, a law professor at George Washington University, wrote that the rationale behind the Supreme Court’s decision could cause some to reconsider polyamorous families, in which more than two people are in a marriage-like union. In an opinion piece for The Washington Post, Turley pointed to what he described as Supreme Court Justice Anthony M. Kennedy’s finding of “a right to marriage based not on the status of the couples as homosexuals but rather on the right of everyone to the ‘dignity’ of marriage.”

“What about polyamorous families, who are less accepted by public opinion but are perhaps no less exemplary when it comes to, in Kennedy’s words on marriage, ‘the highest ideals of love, fidelity, devotion, sacrifice, and family’?” Turley wrote. “The justice does not specify.”

Kennedy wrote in the majority opinion that the discrimination against same-sex couples is unconstitutional because it’s linked to prejudice. On the other hand, Ilya Somin, a law professor at George Mason University School of Law, said it’s difficult to identify the sort of prejudice against polygamous families that Kennedy cited as motivating unconstitutional prohibitions against same-sex marriage.

“With polygamy, it’s much tougher to find a group that would be sympathetic to the public where this group would suffer greatly if we didn’t have polygamy available,” Somin said. “The road to success for polygamy will be a much tougher one than same-sex marriage.”

Polygamy’s few supporters argue the practice can’t be popularized yet because there isn’t a public face for it since the practice of getting into a plural marriage is illegal. Right now, the arguments are being made on a more academic or legal level than at a grassroots activism level.

Caught between those on both sides of a political spectrum who argue the state should allow consenting adults to marry whomever they please, polygamists have not seen much mainstream support historically. Support has increased from 5 percent in 2006 to 16 percent today, according to Gallup. The biggest one-year jump in public approval came in 2011, after TLC’s “Sister Wives” about a polygamist family first aired.

Although some Mormons practiced polygamy in the 19th century, the Church of Jesus Christ of Latter-day Saints has banned the practice since 1890. Some Muslims in the United States are quietly in plural marriages.

A federal judge struck down parts of Utah’s anti-polygamy law in 2013, saying the law violated the “Sister Wives” family’s right to privacy and religious freedom. The state’s appeal of the ruling is pending in the U.S. Court of Appeals for the 10th Circuit.

Because the majority opinion doesn’t address why same-sex marriage should be limited to two individuals, polygamy has returned to the spotlight, said Eugene Volokh, a professor at the University of California at Los Angeles’s school of law and the namesake blogger at The Volokh Conspiracy.

If the opinion argued that the opposite-sex-only marriage rule was simply irrational, one could argue that not recognizing polygamy would be rational: recognizing polygamy would impose extra burdens on the government because of the questions raised about insurance coverage, splitting property and other issues.

“I think the argument for requiring the government to recognize polygamous marriage isn’t ridiculous, but I doubt that the court will buy it,” Volokh said. “The policy arguments against polygamous marriages are pretty strong.”

Six Supreme Court decisions have upheld bans on polygamy and public support for polygamy remains low, so it’s unlikely the courts will change the laws anytime soon, said John Witte Jr. a law professor at Emory University who recently published “The Western Case for Monogamy over Polygamy.”

Opposition to polygamy has focused on the potential harm directed toward women and children, because studies have found correlations to abuse and other problems. But proponents historically saw plural marriage as a social welfare system, a defense against sexual abuse and possibly a means of increasing the opportunity for women to marry in times of war, Witte said. Today, arguments in favor of polygamy focus more on sexual autonomy and individual choice.

“Because the definition of marriage or the form of marriage has changed and we’re open to constitutional change, it’s inevitable for this to be contested,” Witte said. “I wouldn’t be surprised if the issue of polygamy gains momentum, but I would be surprised if the court’s opinion changes in my lifetime.”

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