In the New York Daily News, Cato Institute Chairman Robert Levy makes the conservative argument for marriage equality:

No compelling reason has been proffered for sanctioning heterosexual but not homosexual marriages. Nor is a ban on gay marriage a close fit for attaining the goals cited by proponents of such bans. If the goal, for example, is to strengthen the institution of marriage, a more effective step might be to bar no-fault divorce and premarital cohabitation. If the goal is to ensure procreation, then infertile and aged couples should be precluded from marriage.

Instead, most states have implemented an irrational and unjust system that provides significant benefits to just-married heterosexuals while denying benefits to a male or female couple who have enjoyed a loving, committed, faithful and mutually reinforcing relationship over several decades. That’s not the way it has to be. Government benefits triggered by marriage could just as easily be triggered by other objective criteria, leaving the definition of marriage in the hands of private institutions.

Yet our politicians, unwilling to privatize marriage, seem congenitally unable to extricate themselves from our most intimate relationships. One would hope, in the coming months and years, that more enlightened federal and state legislators will have the courage and decency to resist morally abhorrent and constitutionally suspect restrictions based on sexual orientation. Gay couples are entitled to the same legal rights and the same respect and dignity accorded to all Americans.

Read more in the New York Daily News.