Political divisions of the United States Defense of Marriage Act was always a false construct.

Enacted in the midst of the 1996 election season—when conservative forces were raising a ruckus about the "threat" posed by same-sex marriage—it was passed by Congress and signed into law by President Clinton in 1996 in an attempt to turn the volumn down on the issue by formally, if coherently, defining marriage as enterprise that could be entered into only by a man and a woman.

The law was blatantly discriminatory, and as a candidate the presidency, Barack Obama described it as "abhorrent" and "an unnecessary imposition on what had been the traditional rules governing marriage and how states interact on the issues of marriage."

"Federal law should not discriminate in any way against gay and lesbian couples, which is precisely what DOMA does," said candidate Obama in a statement that succinctly summed up the reasons for overturning the law.

Now, in response to a lawsuit brought by the group Gay and Lesbian Advocates and Defenders against the Obama administration’s Office of Personnel Management on behalf of eight married gay couples and three surviving spouses who were denied federal spousal rights and benefits because of DOMA, a federal judge has recognized the logic of those arguments.

The question is whether the president and his Justice Department will operate along the lines voters presumed it would when they elected Obama as a supporter of LGBT rights.

The unfortunate prospect is that the president will not do so.

Technically, the administration is in a process of "reviewing the decision" and had not yet decided whether to further defend DOMA. But, last year, when the department filed court briefs seeking to preserve DOMA, spokeswoman Tracy Schmaler suggested that "until Congress passes legislation repealing the law, the administration will continue to defend the statute when it is challenged in the justice system."

So the general expectation in Washington is that, with the president’s blessing, Attorney General Eric Holder’s Justice Department lawyers will appeal of the ruling by Massachusetts Federal Judge Joseph Tauro, who has ruled that DOMA "plainly encroaches" on the right of the states to make determinations regarding marriage. As Judge Tauro explained it: "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."

That’s the right read of the legislative history, and of the law. And, while Tauro’s decision applies only to Massachusetts, a state that allows same-sex marriage, its significance extends far beyond the Bay State’s borders.

Were the Justice Department to accept the Tauro’s decision as constitutionally sound and appropriate, as federal and some state officials did when the courts began to strike down discriminatory laws during the segregation era, this could be a breakthrough moment in the struggle for marriage equality.

That’s how Congresswoman Tammy Baldwin, D-Wisconsin, a lawyer and a member of the House Judiciary Committee who was the first open lesbian elected to Congress, interpreted it.

Said Baldwin:

I am thrilled by Judge Tauro’s decision that declares part of the Defense of Marriage Act (DOMA) unconstitutional. This is a tremendous victory for all who believe in equal rights and a dramatic confirmation of justice under law.

By ruling that DOMA violates the Fifth and Tenth Amendments of the US Constitution, Judge Tauro affirmed states’ rights of sovereignty and individual rights to due process. Put simply, his rulings confirm what we already know—there is no legal basis for discrimination against same-sex couples.

The right of same-sex couples to marry with the same protections, benefits and obligations as straight couples may, ultimately, be decided by the Supreme Court. The long march to full equality is not yet over, but now is a time to rejoice in this victory.

That is the language of a civil rights campaigner, a believer in the rule of law and an official who takes seriously her oath to defend the Constitution.

It is language that President Obama and Attorney General Holder should echo.