1) It's odd that the Court even addressed the argument, because it is so obviously irrelevant to the ruling. Having found two independent doctrinal grounds for subjecting the marriage law to strict scrutiny---denial of the fundamental right to marriage and discrimination on the basis of sexual orientation---the Court could have simply said that it did not need to reach the question of whether the law was also a form of impermissible sex discrimination. Yet the Court's conclusion that opposite-sex-only marriage is not sex discrimination can now be invoked by opponents of same-sex marriage in other jurisdictions, who will say something like: Even the super-liberal California Supreme Court did not think that sexual orientation discrimination counts as sex discrimination, so it clearly should be understood differently here as well. And in some of the jurisdictions in which this argument is advanced, the notions that marriage is a fundamental right and that sexual orientation is a suspect classification will not be available. Defeat of the argument that sexual orientation discrimination = sex discrimination may not have mattered in this case, but it could be crucial in another jurisdiction.
2) The idea that same-sex marriage restrictions should be struck down as a form of sex discrimination is often called "the Loving analogy," because it rests on a logic drawn from Loving v. Virginia, the U.S. Supreme Court case invalidating Virginia's anti-miscegenation law. It goes like this: If telling a black man that he can't marry a white woman because their races differ is race discrimination, then telling a man that he can't marry a man because their sexes are the same is sex discrimination. The California Supreme Court relied on its own decision invalidating an anti-miscegenation law, Perez v. Sharp (1948), for the proposition that the fundamental right to marry is not limited by its precise history, but the Court rejected the Loving analogy in its standard form: Anti-miscegenation laws express the social meaning of white supremacy, the Court said, but same-sex marriage prohibitions are not an expression of patriarchy (or some other form of sex/gender subordination).
3) There is pretty clearly a sense in which the California Court is right, but that sense does not (or should not) exhaust the scope of equal protection. Although the particular law at issue in Loving was clearly an expression of white supremacy, imagine a case in which it were not. Suppose a state forbade interracial marriage on aesthetic grounds alone. Wouldn't we still want to say that such a law constitutes race discrimination? And wouldn't that conclusion be independent of the fact that marriage is a fundamental right? Surely a law forbidding interracial bowling is an instance of race discrimination, even though there is no fundamental right to bowl and even if the law were in fact adopted for reasons having nothing to do with claims about the superiority or inferiority of various races.
4) What's really going on---and the California Supreme Court opinion gestures incompletely in this direction---is that the California Court is much less formalist than the U.S. Supreme Court. Here's what the California Supreme Court said last week:
a statute that treats a couple differently based upon whether the couple consists of persons of the same race or of different races generally reflects a policy disapproving of the integration or close relationship of individuals of different races in the setting in question, and as such properly is viewed as embodying an instance of racial discrimination . . . . [I]n realistic terms, a statute or policy that treats same-sex couples differently from opposite-sex couples, or that treats individuals who are sexually attracted to persons of the same gender differently from individuals who are sexually attracted to persons of the opposite gender, does not treat an individual man or an individual woman differently because of his or her gender but rather accords differential treatment because of the individual’s sexual orientation.The California Court is, in this passage and throughout the relevant section of the majority opinion, rejecting the sort of formalism one sees in the U.S. Supreme Court, in which the relevant threshold question for applying heightened scrutiny is whether the government has used a suspect or quasi-suspect CLASSIFICATION. Understood in those terms---what the California Supreme Court called a "semantic" argument with some appeal---laws forbidding same-sex marriage unquestionably do constitute sex discrimination.
5) Accordingly, we have an answer to the problem I identified above in 1). A jurisdiction can justifiably reject the Loving analogy only if it more generally rejects formalism in its equal protection jurisprudence. Thus, a state high court that applies the same exacting scrutiny to affirmative action programs as to programs that disadvantage traditionally disadvantaged groups---i.e., a state high court that practices equal protection formalism with respect to affirmative action---should not be able to reject the formalism of the Loving analogy. In other words, the liberal California Supreme Court could reject the Loving analogy because of its commitment to a vision of substantive equality. A more conservative state high court, with a more formal vision of equality, should accept the Loving analogy.
Not that I'm naive enough to think that this will happen.
Posted by Mike Dorf