A three-judge panel hearing oral arguments on Monday in the appeal of California's Proposition 8 hinted that they will support a narrow ruling against the gay marriage ban.

The appeal before the Ninth U.S. Circuit Court of Appeals in San Francisco comes after U.S. District Judge Vaughn R. Walker ruled the law unconstitutional in August.

The court first examined whether ProtectMarriage.com, the conservative group that put Proposition 8 on the ballot, and Imperial County have the legal authority, or standing, to appeal Walker's ruling. The groups intervened in the case after Governor Arnold Schwarzenegger and governor-elect Jerry Brown, as attorney general, refused to defend the law in court. In his ruling, Walker said he doubted the group's legal standing because they are not directly affected by the law.

Charles Cooper, a lawyer for the defense, argued that society has an interest in supporting relationships that can bear children.

“When a relationship between a man and a woman becomes a sexual one, society has a vital interest,” he said.

“That sounds like a good argument for prohibiting divorce,” Judge Stephen Reinhardt responded. “But how does it relate to having two males or two females marry each other and have children as they have in California? I don't understand how that argument says we ought to prohibit that?”

The judge's questions suggested they are considering a narrow ruling against the ban. One that overturns Proposition 8 without directly impacting similar bans in other states.

“All three judges seemed genuinely interested in a narrow framing of the case – as one about whether California has a legitimate interest in taking away the label 'marriage' from lesbian and gay Californians while leaving intact a comprehensive domestic partnership regime that provides the rights and benefits of marriage,” Doug NeJaime, an associate professor at the Loyola Law School, said.

Ted Olson, an attorney for the plaintiffs, indulged the court by saying he would be satisfied with a ruling that struck down Prop 8 as unconstitutional because it ended a pre-existing right. Prop 8 overruled a 2008 state Supreme Court decision that legalized gay marriage for a brief time. Only one other state, Maine, might be impacted by such a narrow ruling.

“If this less sweeping, more California-centric understanding of the case prevails at the Ninth Circuit, the U.S. Supreme Court would be directly presented with a way to rule in favor of lesbian and gay equality while leaving intact the discriminatory laws of the majority of the states. The bigger question of a nationwide right to marry for same-sex couples would continue to wait for its day in court,” he added.