At oral argument the state‘s lawyer was asked whether “Indiana’s law is about successfully raising children,” and since “you agree same-sex couples can successfully raise children, why shouldn’t the ban be lifted as to them?” The lawyer answered that “the assumption is that with opposite-sex couples there is very little thought given during the sexual act, sometimes, to whether babies may be a consequence.” In other words, Indiana’s government thinks that straight couples tend to be sexually irresponsible, producing unwanted children by the carload, and so must be pressured (in the form of governmental encouragement of marriage through a combination of sticks and carrots) to marry, but that gay couples, unable as they are to produce children wanted or unwanted, are model parents—model citizens really—so have no need for marriage. Homosexual couples do not produce unwanted children; their reward is to be denied the right to marry. Go figure.
It's kind of a perfect illustration of the tension between the 2 schools of thought about what marriage is. The sentiment that has been so incredibly fertile for the "marriage equality" movement is that marriage is a special and sacred privilege or reward for people who are in love and should be extended to everyone who falls in love, no matter who they fall in love with. The other view -- and it's the view I've taken most of my life, though naturally it has been complicated by events in my personal life -- is that marriage is a form of social control. A way for men to control women, for women to control men, for the church and state to control people's sexuality and family and intimate lives.
I think marriage is certainly both, and many other things, and mostly it is what we want to make of it. So Posner loses me a little when he ridicules the idea that marriage provides some pressure on men to support the babies they make even if they hadn't considered the consequences before the fact. Because it is true that straight people are much more inclined to reproduce accidentally, and if the state has an interest in the welfare of children (which neither side in this debate disagrees with), then its support of marriage for heterosexuals has a quality not necessary for homosexuals. That seems pretty straightforwardly true and when he dismisses it so snarkily, I think he undermines the seriousness of the implications of laws and policies governing marriage and family life.
The "shotgun wedding" aspect of marriage is maybe outdated in most cases (now that single mothers and divorce are so ubiquitous and accepted) and it's obviously only one among many reasons that people might want to marry, but I think it at least deserves to be addressed seriously. I think this is the first time one of those Christiany "it's for the children" arguments has struck me as even ever so slightly convincing.