SAN FRANCISCO (Reuters) - A federal court declined an appeal to revisit California's gay marriage ban on Tuesday, clearing the way for the Supreme Court to consider whether the ban violates the U.S. Constitution.
Supporters of the ban, Proposition 8, have lost two rounds in federal court. Tuesday's decision now passes the issue into the hands of the top U.S. court, which, while conservative-leaning, has been sympathetic towards gay rights.
The Supreme Court could agree to hear the matter in a session beginning in October, ahead of the November 6 U.S. presidential election, and putting it on track to decide the case within a year.
President Barack Obama last month turned gay marriage into a 2012 campaign issue, saying he believed same-sex couples should be able to marry. His Republican opponent Mitt Romney disagrees.
The Supreme Court could turn its next session into a gay-rights blockbuster, with two major cases coming at the same time. In addition to the California decision on Proposition 8 by the 9th U.S. Circuit, a Boston federal appeals court recently struck down part of the federal law rejecting same-sex marriage, the Defense of Marriage Act.
"The timing is too perfect," said Thomas Goldstein, a Washington-based attorney who practices before the Supreme Court, adding that the argument would resemble this year's proceedings on legal challenges to Obama's health care plan.
The vast majority of U.S. states limit marriage to opposite-sex couples, and popular votes have consistently approved bans on widening those rights.
But polls show growing acceptance of same-sex nuptials, which have been legalized in eight states and the District of Columbia, thanks to votes by legislators and court decisions.
In the California case, proponents of Proposition 8 - which passed in 2008 with 52-percent support - argued that voters had the right to limit marriage to opposite-sex couples. Such relationships were the best for producing and rearing children, they said.
Opponents responded that allowing same-sex couples to marry would not infringe on the rights of opposite-sex couples. Two lower courts agreed.
"Proposition 8 serves no purpose, and has no effect, other than to lessen the status and human dignity of gays and lesbians in California," the 9th Circuit Court said in February.
Only three out of 26 active 9th Circuit judges opted to publicly disagree with the decision to pass up revisiting the case on Tuesday. Those three Republican-appointed judges said the court's ruling against the ban used a "gross misapplication" of a Supreme Court decision, and had overruled seven million California voters.
TO THE SUPREME COURT, OR NOT?
The Supreme Court could refuse to hear on the case, thereby lifting the California ban, but leave unresolved the broader issue of a constitutional right to same-sex marriage.
If the Supreme Court does take it up, insiders will be watching Justice Anthony Kennedy, a conservative who is seen as the swing vote of the nine court members. He has written two important decisions which came down firmly on the side of same-sex couples, but shied away from the question of gay marriage.
In 2003 in Lawrence v. Texas, he wrote that the decision to strike down a ban on sexual acts between same-sex couples did not involve whether the government must recognize other homosexual relationships.
"Do not believe it," dissenting Justice Anthony Scalia responded at the time, arguing that Kennedy's decision laid out the legal logic for recognizing gay marriage.
Helen Knowles, a professor at Whitman College who has written a book about Kennedy's opinions, said she thought Kennedy would be "squarely" in favor of expanding the rights of gay Americans - even if this meant a broader marriage opinion than the lower appeals courts have written.
Appeals courts have so far declined to rule broadly on whether marriage is a fundamental human right for same-sex couples as well as heterosexuals.
Last week, the 1st Circuit Court of Appeals in Boston ruled that the federal Defense of Marriage Act unconstitutionally denied benefits to same-sex couples in a state where gay marriage was legal, and the February ruling by the 9th Circuit limited itself to declaring Proposition 8 unconstitutional.
"I think the California case would have a greater landmark impact," Knowles said.
On Tuesday, the 9th Circuit kept the decision ending the ban on hold for 90 days, to allow for an appeal to the Supreme Court.
California is the most populous U.S. state and the home of Hollywood and hippies, but it has a socially conservative side too. That leaning was clear in the 2008 ballot that enacted Proposition 8.
"We're not end of the line yet, but we are vastly closer," said Theodore Olson, an attorney for the two gay couples challenging the ban. His partner in the case, David Boies, predicted that the Supreme Court would take on the California case, the Boston case, or both.
An attorney for the supporters of the ban said his team was preparing for the next round. "We will promptly file our appeal to the nation's highest court and look forward to a positive outcome on behalf of the millions of Californians who believe in traditional marriage," Andrew Pugno said in a statement.
(Editing by Sandra Maler and David Brunnstrom)