A U.S. district judge in Boston, Massachusetts declared Thursday in two separate rulings that a nation-wide ban on same-sex marriage is unconstitutional because it prohibits individual states from defining what marriage is and is not.

In one decision, U.S. District Judge Joseph Tauro, according to a breaking Associated Press report, "said the act forces Massachusetts to discriminate against its own citizens."

Obama administration attorneys had argued that in administering federal benefits, the federal government has the right to require marriages are between a man and a woman. That case is Gill v. Office of Personnel Management, which was litigated by attorneys for the Boston-based rights group Gay & Lesbian Advocates & Defenders (GLAD).

"GLAD is representing seven married gay couples and three surviving spouses from Massachusetts who have been denied federal benefits because of the 1996 law that defines marriage as a heterosexual union for federal agencies," gay advocacy Web site On Top noted.

Gill v. Office of Personnel Management is one of several cases expected to make it all the way to the Supreme Court of the United States, the electronic magazine added.

In another decision also issued Thursday, Judge Tauro noted that the Defense of Marriage Act, passed in 1996 during the Clinton administration, violated protections inherent to the 10th Amendment to the Constitution.

"The federal government, by enacting and enforcing DOMA, plainly encroaches upon the firmly entrenched province of the state, and in doing so, offends the Tenth Amendment," he ruled, according to the AP. "For that reason, the statute is invalid."

That ruling came in a lawsuit filed by Massachusetts Attorney General Martha Coakley, who contended that legally married gay couples in Massachusetts had been unjustly denied federal benefits.

In a stroke of irony, the decision would appear to be not just a victory for gay rights advocates, but also for many conservatives to whom the 10th Amendment has become something of a rallying cry. However, instead of emphasizing the 10th Amendment as a means of expanding their fellow citizens' civil rights, most of the so-called "Tenthers" who vehemently preach the text are opposed to gay marriage and raise their voices in objection to government spending and regulations on big business.

Whether conservatives will view the ruling as a victory for their favored portion of the constitution remains to be seen.

Five states thus far have legalized same-sex marriage.

To read the full decision in Gill v. Office of Personnel Management, click here.