Why the Constitution would protect polygamy

Now that a U.S. appeals court has declined to strike down Utah's bigamy laws, it's reasonable to ask: What does the Constitution, properly interpreted, have to say about the topic?

Legally speaking, the issue can be split in two. The first question is whether a state may criminalize marriage to more than one person. The second is whether, in light of the U.S. Supreme Court decision last year to require states to recognize same-sex marriage, there now exists a fundamental right to marry more than one person — and to make states treat plural marriages on equal terms with marriages between two people.

The first one is easier. Under current laws in many states, if you're already married, then it's a crime to marry another person as well. These laws are part of our legal tradition, and perhaps make some sense if you restrict them to bigamists who marry a second spouse without telling them about the existence of the first.

But consider the consolidation of constitutional rights that already exist: I can have sex with any consenting adult under the court's 2003 precedent of Lawrence vs. Texas, which struck down anti-sodomy laws. I can freely engage in any religious ritual under the free-exercise clause of the First Amendment. And using my freedom of speech, I can talk about both my sexual relationships and religious rituals that I've used to solemnize them.

Given these rights, it seems strange that the law prohibits me from forging sexual relationships with multiple partners and calling them my spouses after we've made a mutual religious commitment. If I called them girlfriends or boyfriends, I'm protected by the Constitution. So, it seems indefensible that I can't call them wives or husbands.

It might just be plausible to say that I can't call my life partners legal wives or husbands so long as the law doesn't recognize plural marriages. But even a rule prohibiting me from doing so on the grounds that it might mislead others is almost certainly unconstitutional. In U.S. vs. Alvarez in 2012, the court struck down a law that criminalized lying about winning a medal of honor. The right to lie is therefore enshrined in the constitutional pantheon. If I can lie about a medal, why not about marriage?

The harder question is whether the state should be obliged to recognize plural marriage and treat polygamists equally with those who marry one person. In the Supreme Court's gay-marriage decision, Obergefell vs. Hodges, Justice Anthony Kennedy said that there was a fundamental right to marry the person of your choice and that everyone is owed the opportunity for the equal dignity of marriage regardless of sex or sexual orientation. But he did not say those rights could be extended to polygamy and polygamists.

Logically, however, that extension is warranted unless the government has a compelling interest in preventing plural marriage. Start with the fundamental right to choose a partner. Suppose I am not married and want to choose someone who is already married. My autonomy demands that I be free to make that choice, much as I should be able to choose a partner regardless of that person's sex.

Then there's the question of equal dignity. If all humans are inherently entitled to have their marriage choices respected and acknowledged by the government, there's no good reason to exclude people who choose plural marriage. The fact that some religions — Muslims and fundamentalist Mormons, for example — tend to be the people seeking this right gives a further free-exercise reason to treat them equally.

Often, the Supreme Court asks whether a fundamental right is trumped by a compelling state interest to the contrary. This does not seem to be such a case. Considering that the law already allows me to share my life with multiple partners, what interest can the state have in refusing recognition to that relationship? Certain versions of plural marriage may be associated with cultlike behavior or abuse. But the solution is to outlaw abuse and coercion, not polygamy itself.

Practical legal problems regarding child custody and property division would arise in plural marriages. And it remains to be worked out whether such marriages would consist of overlapping bilateral relationships or comprehensive joint ones. But these are the kinds of problems that family law excels in solving. Plural marriage, after all, is not some newfangled invention. It's in the Bible, and was known to most ancient civilizations in one form or another. Its roots lie even deeper than those of gay marriage. It's time the Supreme Court recognized it.

Noah Feldman, a Bloomberg View columnist, is a professor of constitutional and international law at Harvard.