The U.S. Court of Appeals for the First Circuit ruled unanimously today that the so-called Defense of Marriage Act (DOMA) was unconstitutional. While it left to the Supreme Court the question of whether there is a constitutional right to marry, the jurists were clear that denying federal benefits to legally married couples in the state of Massachusetts was a denial of equal protection and interfered with a state’s right to define marriage.

Gill v. Office of Personnel Management and Massachusetts v. United States is the 2010 case of seven same-sex married couples, plus three surviving spouses of gay married couples, who were denied federal benefits. This wasn’t a case of trying to get the federal government to grant a new right. This was a case demanding the federal government do for lawfully wedded same-sex couples what it does as a matter of course for heterosexual married couples. The appeals court’s ruling addressed this head-on.

[M]any Americans believe that marriage is the union of a man and a woman, and most Americans live in states where that is the law today. One virtue of federalism is that it permits this diversity of governance based on local choice, but this applies as well to the states that have chosen to legalize same-sex marriage. Under current Supreme Court authority, Congress' denial of federal benefits to same-sex couples lawfully married in Massachusetts has not been adequately supported by any permissible federal interest.

As Chris Geidner at Metro Weekly reports, this “is the first instance of a federal appellate court striking down any portion of the 1996 law.” This also comes after the Obama administration stopped defending DOMA in court and after President Obama himself came out in favor of marriage equality earlier this month.

Public opinion is changing on the question of marriage equality, too. But the only opinions that will ultimately matter on the constitutional right of same-sex couples to marry rests with the nine justices of the Supreme Court. Your guess is as good as mine as to how they’d rule.