On March 26 and 27, the U.S. Supreme Court will hear oral arguments in two cases challenging the definition of marriage as the union of one man and one woman. In Hollingsworth v. Perry, they will consider the constitutionality of the definition as enshrined in the California state constitution by voters in that state when they adopted “Proposition 8” in 2008 (effectively reversing the decision of the California Supreme Court to impose same-sex “marriage” earlier that year). In Windsor v. United States, they will consider the constitutionality of the same definition of marriage being adopted for all purposes under federal law through the 1996 Defense of Marriage Act (DOMA).

In anticipation of those oral arguments, I am offering a series of blog posts with questions and answers related to the issue. Today, we look at the question of whether laws defining marriage as the union of one man and one woman are comparable to the laws some U.S.states once had which banned interracial marriage.

Isn’t prohibiting homosexual “marriage” just as discriminatory as prohibiting interracial marriage, like some states used to do?

This analogy is superficially appealing, since both such laws involve some restriction on one’s choice of marriage partner. But no one has an unlimited choice of marriage partner, because no one can marry a child, a close blood relative, or a person who is already married. The differences between laws limiting marriage based on race and laws defining marriage based on the complementarity of the sexes are much greater.

Laws against interracial marriage served only the purpose of preserving a social system of racial segregation. This was both an unworthy goal and one utterly irrelevant to the fundamental nature of marriage.

Bridging the divide of the sexes by uniting men and women, on the other hand, is both a worthy goal and a part of the fundamental purpose of marriage, common to all human civilizations.

Ironically, this means that in one key respect, it is the supporters of marriage redefinition who resemble the opponents of interracial marriage. Both merely exploited the institution of marriage to advance a social goal that has nothing to do with the purpose of marriage, which is to promote responsible procreation. Virtually everyone now opposes the goal of one (racial segregation), whereas society remains sharply divided on the other (the forced affirmation of homosexual relationships), but this is ultimately irrelevant. Neither of these goals is related to the public purposes of marriage.

Allowing a black woman to marry a white man does not change the definition of marriage, which requires one man and one woman.  Allowing two men or two women to marry would change that fundamental definition.