Yesterday, a federal judge in Massachusetts struck down a key part of the Defense of Marriage Act on two separate constitutional challenges. Judge Joseph Tauro, a Nixon appointee, ruled that the provision banning the federal government from recognizing gay people’s marriages violates the Constitution’s guarantee of equal protection, and the principle of state sovereignty.

Tauro’s opinion in the equal protection case includes some strong words on the motivation behind DOMA, the 1996 law designed to push back against states granting marriage equality. The main purpose of the law was to disadvantage a particular set of people simply out of dislike for them, he writes…and that sort of motivation doesn’t pass constitutional muster:

This court simply “cannot say that [DOMA] is directed to any identifiable legitimate purpose or discrete objective. It is a status-based enactment divorced from any factual context from which [this court] could discern a relationship to legitimate [government] interests.” Indeed, Congress undertook this classification for the one purpose that lies entirely outside of legislative bounds, to disadvantage a group of which it disapproves. And such a classification, the Constitution clearly will not permit.

In the wake of DOMA, it is only sexual orientation that differentiates a married couple entitled to federal marriage-based benefits from one not so entitled. And this court can conceive of no way in which such a difference might be relevant to the provision of the benefits at issue. By premising eligibility for these benefits on marital status in the first instance, the federal government signals to this court that the relevant distinction to be drawn is between married individuals and unmarried individuals. To further divide the class of married individuals into those with spouses of the same sex and those with spouses of the opposite sex is to create a distinction without meaning. And where, as here, “there is no reason to believe that the disadvantaged class is different, in relevant respects” from a similarly situated class, this court may conclude that it is irrational prejudice that motivates the challenged classification. As irrational prejudice plainly never constitutes a legitimate government interest, this court must hold that Section 3 of DOMA as applied to Plaintiffs violates the equal protection principles embodied in the Fifth Amendment to the United States Constitution.

It seems pretty straight-forward to conclude that the Constitution doesn’t allow Congress to discriminate against people just because they dislike them…but, of course, conservative groups are already calling it “activism.”