By Lawrence Hurley and David Ingram
WASHINGTON (Reuters) - In President Barack Obama's latest act in support of gay rights, his administration on Thursday urged the U.S. Supreme Court to allow same-sex marriages to resume in California.
The administration filed a friend-of-the-court brief in a case set to be argued on March 26 on whether California's 2008 measure, known as Proposition 8, is unlawful under the U.S. Constitution.
In the brief, Solicitor General Donald Verrilli argued that states cannot give all the benefits of marriage to gays and lesbians without calling it marriage.
That position, if adopted by the court, would affect not just California but also seven other states that offer benefits to same-sex couples while barring marriage.
The states allow civil unions or domestic partnerships providing all or virtually all state-level spousal rights but not the "marriage" designation.
They are Delaware, Hawaii, Illinois, New Jersey, Rhode Island, Nevada and Oregon.
Attorney General Eric Holder said in a statement that the filing "seeks to vindicate the defining constitutional ideal of equal treatment under the law."
Verrilli wrote that the California law "provides to same-sex couples registered as domestic partners all the legal incidents of marriage, but it nonetheless denies them the designation of marriage allowed to their opposite-sex counterparts."
As a result, "the exclusion of gay and lesbian couples from marriage does not substantially further any important governmental interest," he said.
The federal government is not a party in the case and it had been unclear whether the administration would file a brief. Gay rights activists were eager to have it intervene.
The court's nine justices are under no obligation to pay close attention to the administration brief, or any of the dozens of other briefs filed by groups not a party to the litigation, including businesses, religious institutions and states.
The Obama administration already has taken a stand on gay rights in another case before the court, to be argued a day later on March 27. That case challenges the constitutionality of a central part of the 1996 federal Defense of Marriage Act (DOMA), which defines marriage under federal law as being between a man and a woman.
The administration's filing is likely to disappoint those who want to see gay marriage made legal in all 50 states in short order.
Some legal experts have said the so-called "eight state solution" would deter other states from offering some benefits to same-sex couples without going so far as to endorse marriage.
The administration stood by its position in the DOMA case that courts should tread carefully when weighing laws that single out gays and lesbians. Some legal scholars think that if courts follow that logic, no ban on gay marriage could be deemed constitutional.
Holder announced in 2011 that the administration would no longer defend DOMA, the federal law, because it considers the measure a violation of the U.S. Constitution's guarantee of equal protection under the law.
Nine states and the District of Columbia allow same-sex marriage: Connecticut, Iowa, Maine, Maryland, Massachusetts, New Hampshire, New York, Vermont and Washington.
The gay marriage movement has gained momentum since Proposition 8 was passed in 2008. In 2012, voters in Maryland, Maine and Washington approved same-sex marriage.
(Reporting by David Ingram and Lawrence Hurley; Editing by Howard Goller and Xavier Briand)