The Department of Justice on July 1 recommended a federal appeals court in California dismiss a motion promoted by the House of Representatives to dismiss a challenge to the Defense of Marriage Act (DOMA).

The argument came Golinski v. Office of Personnel Management, a case filed by Lambda Legal Defense in which the DOJ initially tried to dismiss the case itself.

Williams Institute Legal Director Jenny Pizer, a former Lambda attorney, noted that, “while this step is fully consistent with the position taken back in February, it was not at all assumed that the Administration would participate actively in the pending DOMA cases.”

Attorney General Eric Holder, on February 23, sent a letter to House Speaker John Boehner, alerting him that the administration considers Section 3 of DOMA to be unconstitutional. Section 3 states that the federal government will not, for any federal purposes, recognize any same-sex marriage. Holder’s letter said the administration would not defend it beyond the First Circuit U.S. Court of Appeals. (The First Circuit, noted Holder, has said that laws treating people differently on the basis of sexual orientation should be examined using the lowest level of judicial scrutiny—rational basis—under which almost any reason can pass muster.)

Holder’s letter said the administration believes laws disfavoring persons based on sexual orientation should have to pass the most stringent judicial review—heightened scrutiny. And it said the administration would argue so in two cases challenging DOMA in the 2nd Circuit.

The Golinski case is in the 9th Circuit. And though the DOJ acknowledges that the 9th Circuit, like the First, has previously held that rational basis review is appropriate for sexual orientation, “we respectfully submit that this decision no longer withstands scrutiny.”

To justify its argument, the DOJ notes that, in 2003 with Lawrence v. Texas, the U.S. Supreme Court struck down laws prohibiting private consensual sex between same-sex partners. And it says “gay and lesbian individuals” fit the bill as a long-oppressed minority—or suspect class. It has been frequently targeted by discrimination, it is a class with limited political power, and it is a class defined by an immutable trait that bears no relationship to the individuals’ ability to contribute to and participate in society.

The brief argues that there is no justification for DOMA’s treating same-sex couples differently and that the record surrounding the law “evidences the kind of animus and stereotype-based type thinking that the Equal Protection Clause is designed to guard against.”

“The Obama Administration is putting very welcome additional flesh on the important bones of Attorney General Holder’s February letter to John Boehner explaining why the Administration won’t defend DOMA any longer,” said Pizer.

Signing the July 1 DOJ brief were Michael Hertz, a deputy assistant attorney general; Melinda Haag, a U.S. attorney; and Arthur Goldberg, assistant branch director.

Pizer said the Hertz brief “gives a detailed and immensely persuasive examination of why antigay laws should be subjected to rigorous constitutional review, including with a very substantial documenting of the systematic mistreatment of gay people by government, the religious and other legally improper reasons for that mistreatment, and further reinforcement of the point that the needs of children are served by equal treatment of all married parents, rather than federal discrimination against some of them.”

Human Rights Campaign President Joe Solmonese said the brief “represents real leadership from the Obama administration and further hastens the day in which we will leave this odious law in the dustbin of history.”

The brief, which typically takes weeks, if not months, to complete, was filed as President Obama was coming under increasing pressure from the LGBT community and the media to speak out in favor of same-sex marriages and marriage equality laws.

In Golinski v. OPM, an employee of the 9th Circuit federal appeals court, is suing to obtain health coverage for her spouse. The federal court provides such benefits to the spouses of straight employees and was prepared to offer them to Golinski. But the Office of Personnel Management, headed by openly gay appointee John Berry, instructed the court’s insurance company, Blue Cross/Blue Shield, to deny the claim, citing DOMA.

DOMA, enacted in 1996, prohibits any federal entity from recognizing a marriage license granted to a same-sex couple.

In March, a federal district court judge granted the DOJ’s initial request that Golinski’s lawsuit be dismissed, agreeing that OPM had a duty to enforce DOMA that trumped the 9th Circuit’s agreement to provide benefits to Golinski.

Lambda has filed an amended complaint and the DOJ brief was submitted to that pending litigation in the U.S. District Court for Northern California. The House’s Bipartisan Legal Advisory Group (BLAG) has filed a motion to intervene in the Golinski case to defend DOMA.