In Washington state, lawmakers voted Wednesday to approve gay marriage, setting the stage for the state to become the seventh in the nation to allow same-sex couples to wed.
Austin Nimocks, a senior lawyer for the Alliance Defense Fund, one of the groups defending the California law, would not reveal the strategic considerations, but promised: "We will do something. I can guarantee that."
Proposition 8 backers could ask the Ninth Circuit to rehear the case with an 11-judge panel, giving more judges on the sprawling court an opportunity to review the merits of Tuesday's ruling.
In that 2-1 ruling, written by Judge Stephen Reinhardt, the Ninth Circuit found that California's gay-marriage ban is unconstitutional, stripping away a previous right to marry without any legal or social justification.
One judge, N. Randy Smith, dissented, giving Proposition 8 backers fodder for either further appeal in the Ninth Circuit or for a petition to the Supreme Court.
Legal scholars, as well as judges and lawyers familiar with the Ninth Circuit, say the ideological math may weigh in favor of Proposition 8 lawyers proceeding directly to the Supreme Court.
A majority of the court's 25 full-time judges must vote in favor of rehearing the case, and the Ninth Circuit's makeup is now tilted toward liberal to moderate judges. Sixteen of the 25 judges are Democratic appointees, although there are legal experts who say there may be judges who agree with Reinhardt but believe the case warrants full review.
Still, the maneuver is "likely to be futile," said Eugene Volokh, a UCLA law professor.
"It's just unlikely they'll get a majority vote for review," said Volokh, a former law clerk for Chief Ninth Circuit Judge Alex Kozinski.
There are wild cards in the equation.
For one thing, any Ninth Circuit judge can unilaterally ask for a vote on a rehearing, effectively settling the question in the short term. And if the court defies the odds and agrees to reconsider, anything goes: The 11-judge panels are picked randomly, and could include any conceivable ideological mix of judges who would take a second look at this week's ruling.
Whatever an 11-judge panel decides, the losing side would then take the case to the Supreme Court.
"It's really the luck of the draw for them," said Margaret Russell, a Santa Clara University law professor who believes it may make sense to take another shot in the Ninth Circuit.
In Washington state, the House passed the gay-marriage bill on a 55-43 vote. The state Senate approved the measure last week. And Democratic Gov. Chris Gregoire is expected to sign the measure into law next week.
Democratic Rep. Jamie Pedersen, a gay lawmaker from Seattle who has sponsored gay-rights bills in the House for several years, said that while he and his partner were grateful for the rights that exist under the state's current domestic-partnership law, "domestic partnership is a pale and inadequate substitute for marriage."
This article contains information from the Associated Press.