Today, the Iowa Supreme Court struck down that state's ban on same-sex marriage.
From what I can tell, the ruling was made on equal protection grounds:
“We have a constitutional duty to ensure equal protection of the law,” the Iowa justices wrote in their opinion. “If gay and lesbian people must submit to different treatment without an exceedingly persuasive justification, they are deprived of the benefits of the principle of equal protection upon which the rule of law is founded.”As I wrote some place in the past, the argument in favor of same-sex marriage through equal protection is fairly simple. The law gives some people the right to marry the consenting adult partner of their choice. Unless there is some "exceedingly persuasive justification" against it, everyone should have that right. There is no reason to restrict the right only to those who wish to marry someone of the opposite sex.
Simple. Conservative arguments against gay marriage often rely on dubious assumptions about the consequences that would follow from the legal recognition of same-sex marriage. For example, it has been argued that the legal recognition of same-sex marriage will somehow incentivize hetereosexuals against getting married -- despite the tax and other social benefits that go along with marriage.
These arguments are so transparent, it is no wonder the Iowa decision was unanimous.
There are other conservative arguments that could be called "formalist." These arguments rest on the assumption that marriage is and always has been defined in a certain way, and that -- for some reason -- the law ought to track that definition, to the exclusion of all other considerations.
These are silly arguments, for several reasons. One reason is that it is not clear how the person making the argument thinks normative content can and should be derived solely from a dictionary definition. I'm not claiming that a commonly accepted definition of a term should _never_ inform the law. But it is hardly the only consideration that matters.
Another formalist argument involves denying that same-sex couples have unequal rights, since they have exactly the same right to marry as opposite-sex couples: that is, they can marry someone of the opposite sex.
This argument piggy backs on the first. There is no way to rebut it directly -- not because it is that powerful of an argument, but because it is barely an argument at all. Marriage has certain essential features. We rely on these features when we distinguish "good" marriages from "bad" ones. A loveless show marriage, for example, qualifies as a "bad" marriage (or, better: it is a bad example of a marriage.)
Why is this? Well, we tend to think that the presence of a loving, committed relationship is an important, if not essential, feature of marriage. Same-sex relationships can exhibit this feature. That value -- which can be present in same-sex relationships to the same degree as opposite-sex ones -- is important, and the law ought to recognize it without prejudice.
But notice, the value -- which we can call the essential value of marriage -- depends in no way on the people in the relationship being of the opposite sex. When the law restricts marriage to opposite-sex couples, it is not protecting the value of marriage; instead, it is diminishing it, because it is placing what is an inessential part of the value of marriage -- the opposite sex part -- on the same level as a feature that is part of the essential value of marriage.
What is important is that we recognize committed, loving relationships; not that we recognize committed, loving relationships between people who happen to be of the opposite sex.
This is a good day for Iowa.