Polygamy is constitutional. Here's why.

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.