A US judge refused to vacate a decision last year that declared California's anti-gay marriage Proposition 8 unconstitutional. Backers of Prop. 8 had wanted the decision thrown out on the grounds that the judge who made the decision is gay and therefore should have recused himself from the case.

Chief US District Judge James Ware said that requiring a gay judge to recuse himself from a case about gay marriage would have set a dangerous precedent.

“The fact that a federal judge shares a fundamental characteristic with a litigant, or shares membership in a large association such as a religion, has been categorically rejected by federal courts as a sole basis for requiring a judge to recuse her or himself,” wrote Judge Ware.

The decision means the ruling of US District Judge Vaughn Walker remains in effect. Prop. 8 backers have appealed that ruling to the Ninth Circuit Court of Appeals. Ultimately, the case could end up before the Supreme Court, many legal analysts say.

Lawyers for the sponsors of Prop. 8, which declared that marriage should be between only one man and one woman, argued that Judge Walker stood to gain personally from his own verdict. Walker revealed the a 10-year relationship with another man publicly after stepping down in February.

But Theodore Olson, a lawyer for two same-sex couples who sued to overturn Prop. 8, argued that expecting judges to reveal portions of their private lives when hearing gay-rights cases could open a Pandora's box.

“What would a judge do who was Mormon, knowing the Mormon Church took such an active role” in campaigning for Prop. 8, Mr. Olson asked, according to the Associated Press. “What would a judge who had a nephew or niece or son or daughter who was gay or lesbian do? We have an unlimited number of permutations of what a judge might be asked to disclose.”

Legal experts said that Ware’s decision is not a shock given that efforts to remove Hispanic judges from immigration cases or to dismiss women judges from gender-discrimination cases have failed.

In this way, the ruling can be seen as a valuable “teachable moment” for those outside the legal field, say experts.

Walker's "sexual orientation was not a basis for his needing to recuse himself any more than a woman judge of reproductive age is disqualified from hearing a challenge to an abortion law or an African-American judge is disqualified from hearing a race discrimination case," says constitutional scholar Erwin Chemerinsky, dean of the University of California at Irvine Law School, in an e-mail.

Pro-same-sex marriage groups said the request to vacate the decision was a veiled attack on Walker's sexual orientation.

"If the argument is valid that Walker necessarily acted out of self interest because he was in a long-term, same-sex relationship, it follows also that a married, heterosexual judge would also act of self-interest [to protect heterosexual marriage] and would have to be disqualified,” says Jim Carroll, interim executive director of Equality California, a nonpartisan group which works to secure legal protections for lesbian, gay, bisexual and transgender people. “To vacate Walker’s decision would have meant dismissing all the legal arguments in his 135-page decision for the sole reason that he is gay.”

The group that filed the challenge, ProtectMarriage.com, said it would appeal and "continue our tireless efforts to defend the will of the people of California to preserve marriage as the union of a man and a woman," according to AP.