SAN FRANCISCO — When voters were asked to sign petitions for a November initiative to limit marriage to opposite-sex couples, they were told the measure would not change state law, which at the time banned same-sex marriage.
But then, after the signatures were gathered, the California Supreme Court ruled that same-sex couples were entitled to wed.
Now supporters of gay marriage are asking the state high court to take the initiative off the ballot, partly on grounds that voters who signed petitions were misled about the measure's potential effect.
"The need for accurate disclosure is particularly acute when the proposed measure will have a profound effect on fundamental rights," gay rights lawyers argue in their lawsuit, which was filed June 20.
The suit, which also contends that the measure would be an illegal constitutional revision, is considered a long shot by some legal analysts. According to the California-based nonpartisan Center for Governmental Studies, the state high court has booted measures off the ballot only eight times -- four since 1983.
Atty. Gen. Jerry Brown, whose office approved the summary accompanying the petition, urged the court Tuesday to reject the argument that signers were misled. In preparing a petition's title and summary, he argued in court papers, the attorney general "should not be required to speculate about how the law might be affected by pending litigation."
Because the proposal would make no change "to the manner in which marriages are currently recognized by the state," Brown's office said, the measure's description was accurate.
"For the court to take an initiative off the ballot, it has to be very clear to the court that the measure doesn't belong on the ballot," said Santa Clara University law professor Gerald Uelmen, an expert on the court. "And in context of this issue, it would be especially explosive."
Nevertheless, Uelmen called the argument over accuracy "powerful."
"As it stands now, the measure would make a very dramatic change in the law," Uelmen said. "It would say to thousands of married couples, 'Your marriage is no longer recognized.' "
The lawsuit contends that petition signers were also misled by a statement that the measure would have no cost. Some economists have projected that same-sex weddings would inject hundreds of millions of dollars into the California economy. Same-sex couples from out of state have been traveling to California for weddings, even though their home states might not recognize their marriages.
Bob Stern, president of the Center for Governmental Studies, expressed doubt that the lawsuit would succeed on any grounds.
"I can't remember the court ever taking something off the ballot when people claimed they were misled into signing it," said Stern, whose group recently published a book about the initiative process. "That just doesn't happen."
Nor did Stern believe the measure amounted to a constitutional revision, which must be initiated by a two-thirds vote of the Legislature.
To be a revision, Stern said, the proposal must fundamentally alter the state constitution, as in, say, a major restructuring of government. He noted that courts in Oregon and Alaska have rejected claims that marriage initiatives were constitutional revisions.
Proposition 8, called the California Marriage Protection Act, states: "Only a marriage between a man and a woman is valid or recognized in California." Proponents said they gathered more than 1.1 million signatures to qualify the measure for the ballot.
Opponents of same-sex marriage have urged the court to reject the lawsuit, warning that it would have "a chilling effect on citizens' exercise of their constitutional rights."
Stern expects the vote on the marriage initiative -- if it stays on the ballot -- to be close.
Voters overwhelmingly decided in 2000 that marriage should be limited to the union of a man and a woman. Views on same-sex marriage have shifted since then, but nonetheless "it would be very unusual for voters to reverse themselves in eight years," Stern said.
The California Supreme Court has not indicated what action it will take on the suit. It could issue a brief order, hold a hearing and make a full-blown ruling or reject the case now but permit advocates to bring the challenge after the election. The ballot goes to the printer in August.