Associated Press

CARSON CITY — Nevada’s decision not to defend the state’s ban on gay marriage leaves a conservative group that pushed for the constitutional amendment to carry on the legal fight alone before a federal appeals court.

More than three dozen groups, states and individuals have filed friend-of-the-court briefs in the case pending before the 9th Circuit Court of Appeals. But only the Coalition for the Protection of Marriage remains to argue for preserving the law being challenged by eight gay, Nevada couples who say it’s an unconstitutional violation of their civil rights.

The coalition orchestrated efforts more than a decade ago to put the constitutional amendment on the ballot, where it received overwhelming support.

Monte Stewart, the coalition’s lead attorney in Boise, Idaho, would not comment Tuesday.

But Jon Davidson, legal director at Lambda Legal, a gay advocacy group representing the Nevada couples in the lawsuit, said the state’s decision “very significantly helps our case.”

“That sends quite a message to the 9th Circuit,” he said Tuesday.

Democratic Attorney General Catherine Cortez Masto announced Monday her office will not defend the amendment defining marriage as between one man and one woman. Republican Gov. Brian Sandoval, a former federal judge and attorney general, agreed, saying Nevada’s law “is no longer defensible in court” after another 9th Circuit ruling that said gays and lesbians cannot be precluded from jury duty because of their sexual orientation. That ruling extended civil rights protections to gays that the U.S. Supreme Court has previously promised only to women and racial minorities.

Still, the case challenging Nevada’s gay marriage ban will proceed in the 9th Circuit in San Francisco. Eight same-sex couples are appealing a ruling by U.S. District Judge Robert Jones in Reno, who upheld the ban in 2012.

Some legal experts say an appellate ruling favoring couples would make it less likely Nevada will become a national test case for the U.S. Supreme Court.

“Where the Nevada attorney general is not defending the law … and same-sex couples win at the appellate court level, then there might not be any case for the Supreme Court to review,” said Douglas NeJaime, a law professor at the University of California, Irvine.

“The big issue is there are so many cases all around the country right now,” NeJaime said. “It’s a race to the Supreme Court.”

But others note that if the court rules in favor of the couples, Nevada could still pursue an appeal to the nation’s highest court for a definitive resolution.

The tactic would be similar to that taken by the Department of Justice in the Defense of Marriage Act, where the government appealed even though it agreed with a lower court ruling against it, Davidson said. The Supreme Court in June struck down part of the federal law that prevented the government from recognizing same-sex marriages.

Another possible outcome, should the couples win, is that gay marriage becomes legal not only in Nevada but possibly other states within the court’s jurisdiction where it is currently banned — Alaska, Oregon, Montana, Idaho and Arizona, Davidson said. California, Hawaii and Washington, the other three states in the court’s circuit, already allow same-sex marriage.