Late last week, a federal judge in Utah struck down part of the state’s law that criminalizes polygamy. The challenge was brought by Kody Brown of the television show Sister Wives. Brown is a polygamist who has one legal wife and three other wives by “spiritual union” based on their religious beliefs.

Polygamy is illegal in all 50 states under state law, and until 1978, there was a federal statute prohibiting polygamy, which the Supreme Court upheld in Reynolds v. United States. Under Utah’s law, passed in 1973, a person is guilty of bigamy if “knowing he has a husband or wife or knowing the other person has a husband or wife, the person purports to marry another person or cohabits with another person.”

After the state opened an investigation into Brown and his four wives, he challenged the law as a violation of various constitutional provisions, including the Due Process Clause and the Free Exercise Clause. In a decision last Friday, Judge Clark Waddoups ruled that Utah’s ban on cohabitation violates free exercise. Citing Utah’s selective enforcement, Judge Waddoups stated that the ban on cohabitation impermissibly targets religious groups that believe polygamy is a core religious practice.

According to the Supreme Court’s current First Amendment jurisprudence, a neutral and generally applicable law that incidentally burdens religious practices is presumptively constitutional. But when a law is shown to impermissibly target religious practices, it must be narrowly tailored to advance a compelling government interest in order to stand. Judge Waddoups found that Utah’s express ban on bigamy withstands scrutiny, but its ban targeting cohabitation does not. He noted that while plural cohabitation based on religious beliefs is banned, “virtually any other cohabitation is unpunished.”

Judge Waddoups also considered whether polygamy and plural cohabitation are “fundamental rights” that deserve special protection under the Due Process Clause. Drawing from the Supreme Court’s 2003 decision in Lawrence v. Texas (striking down a state law criminalizing homosexual sodomy), the Browns argued that there is a “fundamental liberty interest in intimate sexual conduct” that forbids the state from “imposing criminal sanctions for intimate sexual conduct in the home.”

Critics of that decision have repeatedly pointed out that arguments in favor of same-sex conduct are not constitutionally distinguishable from arguments for polygamy. Indeed, in Lawrence, the majority stated that the anti-sodomy law sought “to control a personal relationship that, whether or not entitled to formal recognition in the law, is within the liberty of persons to choose without being punished as criminals.” While Judge Waddoups declined to extend fundamental rights status to polygamy and plural cohabitation, he found the Browns’ arguments “very persuasive.”

This decision does not necessarily legalize polygamy (which 83 percent of Americans believe is morally wrong). But as Supreme Court Justice Antonin Scalia predicted in his dissent in Lawrence, laws that the public considers to be based on moral choices, such as “laws against bigamy, same-sex marriage, adult incest, prostitution…[and] bestiality” are now “all called into question.”