Today’s Ninth Circuit decision striking down California’s Proposition 8 banning same-sex marriage is unpersuasive because it claims that the law fails to meet even minimal “rational basis” scrutiny. Eugene Volokh does a good job of explaining why. But there is an alternative constitutional rationale for striking down same-sex marriage bans that avoids this problem. Proposition 8 is an example of sex discrimination, and must be evaluated under the higher standards of scrutiny applied to gender discrimination by the Supreme Court.
Although the sex discrimination argument has been advanced by several academic advocates of gay marriage, nonacademics tend to be skeptical because the same-sex marriage bans seem to be targeted against gays, not men or women. Hostility towards gays is certainly part of the motivation for bans on same-sex marriage. But that does not prevent these laws from qualifying as sex discrimination. In terms of the way the law is actually structured, a same-sex marriage ban in fact discriminates on the basis of gender rather than orientation. And it is perfectly possible to discriminate on the basis of sex even if the motivation for doing so is something other than sexism.
Consider the hypothetical case of Anne, Bob, and Colin. If same-sex marriage is forbidden, Anne is allowed to marry Colin, but Bob cannot do so. This is so even if Anne and Bob are identical in every respect other than gender. Bob is denied the legal right to marry Colin (and all other men) solely because he is a man. Denial of a legal right solely on the basis of gender is the very essence of sex discrimination.
By contrast, sexual orientation actually has no effect on the way the law operates. Anne is still allowed to marry Colin, even if one of them happens to be gay or lesbian. Bob is denied that right regardless of his sexual orientation. There are actually lots of real world cases where gays or lesbians have entered into opposite-sex marriages, such as the famous example of former New Jersey Governor James McGreevey, a closeted gay man who was married to a woman for many years. McGreevey’s marriage was not illegal, even if his actions were morally dubious.
All of this simply underscores the reality that a ban on same-sex marriage discriminates on the basis of gender rather than orientation – even if the motivation for the discrimination is hostility towards gays and lesbians. Under the Supreme Court’s approach to sex discrimination, any “statutory classifications that distinguish between males and females” are subject to heightened judicial scrutiny. A ban on same-sex marriage pretty obviously “distinguish[es] between males and females.”
Although a ban on same-sex marriage qualifies as sex discrimination, it is not automatically unconstitutional. Since the 1970s, the Supreme Court has taken the view that laws that discriminate on the basis of sex do not violate the Constitution if they can pass “intermediate scrutiny,” which requires them to be “substantially related” to an “important state interest.” If opponents of same-sex marriage are right to claim that Western civilization will fall into deep decline if the practice is allowed, that would be enough to pass the test. Ditto if they can show that same-sex marriage somehow inflicts severe harm on children. But any such arguments would be subject to detailed judicial scrutiny. They would have to be backed by real evidence, and could not pass muster just by being minimally plausible, as under the “rational basis” test.
Some originalists might reject my argument on the grounds that sex discrimination itself is not really banned by the original meaning of the Fourteenth Amendment. I criticized such arguments in this post. For a much more comprehensive rebuttal, see this important recent article by Steven Calabresi and Julia Rickert.
A more moderate originalist critique of my position might hinge on the idea that the framers of the Amendment would not have thought of a same-sex marriage ban as sex discrimination. But it is not hard to figure out that a law under which a legal right is dependent on gender discriminates on the basis of sex. The Framers surely thought that this was justifiable sex discrimination. But that does not mean that it isn’t sex discrimination at all. If asked whether marriage laws circa 1868 limited the right to marry on the basis of gender, most people at the time would surely have said yes. And, as in the case of occupational discrimination against women, the Framers’ view that this form of sex discrimination is constitutionally permissible hinged on dubious factual assumptions that we are not bound by today.
In sum, a ban on same-sex marriage easily qualifies as sex discrimination and is therefore subject to heightened judicial scrutiny. Whether it could withstand such scrutiny is a question I leave to others, though I am skeptical about its chances.
UPDATE: Many commenters seem to be assuming that, in order for a law to qualify as sex discrimination, it has to be motivated by hostility to men or women. Not so. As the Supreme Court puts it, a law can qualify as unconstitutional sex discrimination so long as it is a”statutory classification... that distinguish between males and females.” Similarly, a racial classification counts as racial discrimination for constitutional purposes even if the motives behind it are benign.
It is also not true that a ban on same-sex marriage avoids qualifying as sex discrimination because it affects members of both genders. It still denies rights to both men and women solely on account of their sex. The fact that Bob cannot marry Colin solely on account of gender is not somehow “balanced” by the fact that Anne is similarly forbidden to marry Carol. Similarly, a law banning interracial marriage still qualifies as race discrimination even though both blacks and whites are barred from marrying members of the other racial group.