Superfoo observed in his comment last week to my post discussing President Bush's proposed constitutional amendment banning gay marriage that, should a federal court somewhere determine that gays have the right to marry, the door to legalized polygamy will swing right open.

At first pass, I think the theory that if we allow gay marriage, we have to allow bigamy and polygamy, makes some sense. I would tell you that if you believe that gays have the right to marry on individual liberty grounds, and yet believe that polygamists shouldn't have that same right just because, then you have some serious hypocrisy issues. If we want to argue that gays should have the right marry because it does not affect others extensively and they do it privately with their own consent, if we wish to stay honest with ourselves, we have to admit that polygamists should have the same freedoms, at least in terms of individual liberties.

That said, while I think the law in this country should permit gay marriage, I could also probably articulate a strong argument why polygamists should not have that same right. I just could not do it on individual liberty grounds.

A (very) brief synopsis of constitutional law requires explication here. We often think of constitutional liberties like speech and free exercise of religion as absolute rights, but the law does not actually create this regime. When dealing with any of these rights and laws that restrict them, reviewing courts apply one of three balancing tests. The first, and most difficult for states to pass, goes by the name of strict scrutiny review (the government interest must be compelling and substantial and the law must use the least restrictive means to assert that government interest). Next we have the so-called "intermediate scrutinty" review (government interest must be substantial and important and the law must clearly relate to that interest). The lowest level, and hence most difficult to attack a law under, goes by rational basis review (the government interest must be rational and the law must reasonably relate to that government interest). In non legal terms, it means if you can get the court to apply strict scrutin review to your individual right, you will likely win, and if you get rational basis review, you pretty much have no shot of winning. Intermediate scrutiny is exceedingly difficult to predict both the time for application and the result of its application.

Coming back to gay marriage and polygamy, I shall first assume for the sake of argument that we have recognized the legality of gay marriage and that we have a constitutional challenge to laws prohibiting polygamy. The standard of review that would go to polygamy could make strict scrutiny review just as easily as it could go to rational basis review. But ultimately, I think under any standard of review, polygamy would have a good shot going down. And here's why.

Under the law, marriage is essentially a contract between the two parties joined and the state granting the marriage (and all the other states and the federal government, under the Full Faith and Credit Clause of the Constitution). As a consequence of this three-party contract, we have the ability to file taxes jointly, we have laws governing the succession of property at death, and many other rights based on a relationship between two people, such as health benefits under ERISA and retirement income under Social Security.

The same-sex nature does not offend any of these legal relationships in my opinion or place any serious extra burdens on the states and the federal government. Granting additional tax deductions for health insurance to same sex spouses might reduce the income that comes into the federal treasury a bit, and in theory, we would create a whole new class of potential Social Security recipients. In practice, I think the extra burden on the tax structure and Social Security would not pan out as people might argue, as many of these new classes would likely have their own employment history, and hence will definitely have their own Social Security history and has a good chance of having employer-provided health insurance.

The individual rights we would protect with gay marriage would therefore not cause a huge uproar, legally speaking, in my opinion.

I see a different result with polygamy. In practice we might not have a ton of polygamist marriages that would upset the balances broadly recognized in our state and federal law, because how many people will go out and get hitched to three or four people? But that does not change the fact that we have potential legal relationships that could cause huge problems.

What do we do with joint tax returns, or succession of property laws? What about rules governing beneficiary presumptions where the spouse presumptively receives insurance benefits upon the death of a spouse? What then with two spouses, or three or four? I could articulate other legal situations where the present of three people in a legal relationship between the government and a marriage complicates, but this has already gotten long, so I'll move on.

I can seriously entertain the argument that this complication arises to the level of a compelling state interest. With the kind of burden that polygamy could cause in requiring states and the federal government to reconsider how they treat "marriage" in the face of laws that have always dealt with a relationship between two people, rational basis review would certainly uphold a state law. Strict scrutiny review might unless we could articulate a better response to issue of what we would do with the sudden presence of multiple beneficiaries under the law.

In light of those issues, it seems to me the states should have the freedom to control the number of people to whom they must extend rights appurtenant to marriage. In that sense, while on individual liberty grounds I see no distinction between gay marriage and legalized polygamy, I do see one in the way the law understands marriage. With gay marriage we still deal with a contract between two people and a government. With polygamy, none of those rules apply with any clarity. And I think that fact is enough to create a legitimate legal line between gay marriage and polygamy.