It is an article of our political faith that the state should not be messing around in our private sex lives. We get this from the U.S. Supreme Court's decision in Griswold vs. Connecticut, which held that state laws prohibiting the sale or use of contraceptives are unconstitutional. The court said that using state power to police "the sacred precincts of marital bedrooms" is repulsive to our concept of privacy. Since Griswold, a long line of privacy decisions have protected intimate sexual matters from government intrusion.
Based on this constitutional framework, the state has no business being in the marriage business at all, in the absence of a compelling governmental interest. Yet it does have such a compelling interest: the procreation and nurturing of children. As a society, we need children who will grow up and become wage-earners, entrepreneurs and tillers of soil. Without children coming along, our Social Security system, and government itself, would go broke. Without children, all of us would eventually starve.
Governments act on their compelling interest in future generations by providing benefits associated with marriage. The federal government allows tax deductions for children and Social Security benefits for surviving spouses. We impose the school tax because we deem it in the whole society's best interest to educate the next generation.
It has been argued that special benefits for married couples are a denial of "equal protection." But this argument is based on a misunderstanding. These measures are not government freebies for a privileged sector. They are indirect subsidies compensating parents for the cost of raising children. In reality, however, they amount to only a small fraction of the enormous financial sacrifice parents make for their families.
If you think that the two opposing sides in the marriage debate are talking past each other, you are right. The reason for this is that they are operating from completely different and incompatible models defining the essence of marriage.
The traditional model defines marriage as the lifelong commitment, made by two persons of the opposite sex, to support each other and the children that are the product of their physical union. Marriage as a legal status is based on the physical relationship between a man and a woman, which is based on human biology, which if left to its natural course normally results in children. Society confers this status because of its compelling interest in children.
The revisionist model holds that marriage should not be limited by human biology or reproduction. "Oppositeness," the revisionists say, is not required for a fulfilling sexual relationship; therefore, it should not be required for marriage. People who love each other ought to be given the freedom to marry. Marriage should thus be redefined as a union of hearts and minds: Love should be the only criterion.
It is difficult to understand, however, why unions of hearts and minds need government regulation. The state has no compelling interest in licensing friendships.