Will California gay marriage ruling affect other states?

Wednesday's ruling by a federal judge in San Francisco overturning Proposition 8 shifts the national debate over the definition of marriage in favor of the gay rights camp. For the moment, at least.

If Chief US District Judge Vaughn Walker's decision that declared the state's voter-approved ban on same-sex marriage unconstitutional is eventually upheld by the US Supreme Court, it could overturn laws in 45 states that prohibit gay and lesbian couples from marrying.

For now, however, the decision on Proposition 8 is limited to California. And even in California it may not have an immediate impact.

The lawyers who defended Proposition 8 have appealed the decision and asked Judge Walker to stay his ruling through the appeals process in the US Court of Appeals for the 9th Circuit. Judge Walker has asked lawyers on both sides to present their arguments on the stay by Friday.

In declaring Proposition 8 unconstitutional, Walker issued a sweeping decision on the rights of gays and lesbians. Limiting marriage to heterosexual couples, he said, was an “an artifact of a foregone notion that men and women fulfill different roles in civic life.”

For gay rights groups, it's the landmark decision they had hoped for. In many ways, it's custom tailored for the Supreme Court battle to make the ultimate decision on the same-sex marriage question.

For many on the other side, the ruling smacks of judicial activism and a rejection of voters' rights. Lawyers defending Proposition 8 will no doubt put up an aggressive defense in the appeal process as the case lumbers toward the nation’s highest court.

"This ruling, if allowed to stand, threatens not only Prop 8 in California but the laws in 45 other states that define marriage as one man and one woman," said Brian Brown, president of the National Organization for Marriage, in a statement.

"What's at stake here is bigger than California," said Andrew Pugno, who helped represent the official proponents of Proposition 8, in a statement. "Americans in numerous states have affirmed – and should be allowed to continue to affirm – a natural and historic public policy position like this."

But the decision gave hope to gay rights supporters who have seen same-sex marriage bans succeed at the ballot box every time they were put in front of voters.

"There is a movement toward full equality in terms of marriage laws in the US that has ebbed and flowed over the years. It will continue to ebb and flow," says Betsy Smith, pro-gay marriage group Equality Maine.

Maine's governor signed a bill legalizing gay marriage in 2009 only to have it invalidated by voters later that year.

Now, Ms. Smith says, Walker's ruling shifts the momentum in her side's favor. The states that amended their constitutions over the last half-decade – 30 of them – will see those amendments “fall by the wayside in the next couple years."

What's different about Wednesday's ruling, says Jon Davidson, legal director of the gay rights group Lambda Legal, is that Walker addressed claims made about same-sex marriage and then applied fact and expert testimony to them.

In the short term, however, Davidson cautioned gay rights groups considering challenging other states’ same-sex marriage bans. "It's not so easy to bring one of these cases and win – there was a tremendous amount of resources put into the Prop 8 case," he says.

Still, says Davidson, Wednesday's ruling "has the potential for really changing the conversation and thinking about these issues."