In case 1 (Commonwealth of Massachusetts v. United States Department of Health and Human Services), Judge Joseph Tauro ruled that Congress violated the Tenth Amendment to the U.S. Constitution when it passed DOMA, which narrowed the definition of marriage, under federal law, to be an institution that exists solely between one man and one woman. Under Judge Tauro's ruling, the federal government in so doing violated state sovereignty by treating some couples with Massachusetts' marriage licenses differently than others.
In case 2 (Gill v. Office of Personnel Management), the Gay & Lesbian Advocates & Defenders (GLAD) asked the judge to consider whether DOMA violates the right of eight same-sex couples in Massachusetts to equal protection of the law. The judge's ruling affirms that DOMA does indeed violate the equal protection principles embodied in the Due Process Clause of the Fifth Amendment.
GLAD attorney Mary Bonauto says that DOMA constitutes a "classic equal protection" violation by taking one class of married people in Massachusetts and dividing it into two.
Maura T. Healey, chief of the Massachusetts Attorney General's Civil Rights Division, called DOMA an "animus-based national marriage law" that intrudes on core state authority and "forces the state to discriminate against its own citizens."
Both cases were argued separately in May, and both lawsuits represented specific legal attacks against Section 3 of DOMA - the section that limits 1,000+ federal benefits of marriage to straight couples exclusively. Today's rulings exhibit a relatively quick turnaround, given that some judges take upwards of a year to decide cases. Legal observers anticipate that today's rulings will ultimately be appealed to the U.S. Supreme Court for resolution. The Proposition 8 marriage case also has that potential. Closing arguments in that case were heard in June, but Judge Vaughn Walker has not issued his decision. The next step for all three cases is the U.S. Court of Appeals.