Federal District Judge Arenda Wright Allen issued a ruling today striking down Virginia’s law banning same-sex marriage. The decision follows recent rulings by a federal court in Utah and the New Mexico Supreme Court striking down bans on same-sex marriage in those states.

Interestingly, the Virginia opinion does not rely on the rationale that laws banning same-sex marriage violate the Equal Protection Clause because they constitute discrimination on the basis of gender or sexual orientation. Rather, the ruling is based on the Due Process Clause of the Fourteenth Amendment, which the Supreme Court has long interpreted as forbidding most laws that restrict “fundamental” rights. Several Supreme Court decisions have also ruled that marriage is one such fundamental right, and Judge Allen today concludes that a ban on same-sex marriage violates that right.

In my view, laws banning same-sex marriage are unconstitutional because they discriminate on the basis of sex. I am more skeptical of the Due Process Clause argument adopted by Judge Allen. The Supreme Court has defined the “fundamental” rights protected by that clause as those “deeply rooted in this Nation’s history and tradition.” For obvious reasons, same-sex marriage does not fit that definition very well. Marriage more generally does, of course; but the definition of marriage that was “deeply rooted” was one that (unjustly) failed to include same-sex couples. On the other hand, the gender discrimination rationale avoids this problem, because laws discriminating on the basis of sex are subject to heightened scrutiny regardless of whether they are traditional or not. The whole point of the Equal Protection Clause was to uproot traditional forms of discrimination.

Be that as it may, today’s ruling is part of a growing trend of courts striking down state bans on same-sex marriage. Interestingly, both the Virginia ruling and other similar recent decisions rely heavily on the Supreme Court’s recent ruling in United States v. Windsor striking down part of the federal Defense of Marriage Act. While Windsor was partly based on a federalism rationale that cannot be used to invalidate state bans on same-sex marriage, other parts of the opinion do provide ammunition for people seeking to challenge state law bans. Ironically, some of that ammunition is contained in Justice Antonin Scalia’s forceful Windsor dissent, which Judge Allen quoted as a justification for today’s ruling:

In Windsor, our Constitution was invoked to protect the individual rights of gay and lesbian citizens, and the propriety of such protection led to upholding state law against conflicting federal law. The propriety of invoking such protection remains compelling whenfaced with the task of evaluating the constitutionality of state laws. This propriety is described eloquently in a dissenting opinion authored by the Honorable Antonin Scalia:

As I have said, the real rationale of [the Windsor opinion] is that DOMA is motivated by “bare . . . desire to harm” couples in same-sex marriages. How easy it is, indeed how inevitable, to reach the same conclusion with regard to state laws denying same-sex couples marital status.

Later in his dissent, Scalia suggested that it might still be possible to distinguish Windsor from a case challenging a state law banning gay marriage. But passages like the above undercut such claims.

In the initial version of her opinion, as Josh Blackman pointed out, Judge Allen incorrectly stated that “Our Constitution declares that ‘all men’ are created equal. Surely this means all of us.” She apparently confused the Constitution with the Declaration of Independence. The error was corrected soon thereafter, possibly in response to Josh’s post.

Josh notes that this kind of confusion is common. A 1997 National Constitution Center survey found that some 84% of Americans believe that the Constitution states that “all men are equal.” This kind of confusion is just one small part of the broader problem of widespread political and constitutional ignorance. But it is one thing for an ordinary citizen to confuse the Constitution with the Declaration of Independence and quite another for a federal judge to do so.