The state high court has twice before struck down ballot measures as illegal constitutional revisions, but those initiatives involved "a broader scope of changes," said former California Supreme Court Justice Joseph Grodin, who publicly opposed Proposition 8 and was part of an earlier legal challenge to it. The court has suggested that a revision may be distinguished from an amendment by the breadth and the nature of the change, Grodin said
Still, Grodin said, he believes that the challenge has legal merit, though he declined to make any predictions.
Jennifer Pizer, a staff lawyer for Lambda Legal, said the initiative met the test of a revision because it had far-reaching magnitude.
"The magnitude here is that you are effectively rendering equal protection a nullity if a simple majority can so easily carve an exception into it," she said. "Equal protection is supposed to prevent the targeting and subjugation of a minority group by a simple majority vote."
The first action was filed by the ACLU, the National Center for Lesbian Rights and Lambda Legal. Santa Clara County and the cities of San Francisco and Los Angeles also sued, and Los Angeles lawyer Gloria Allred filed a third suit on behalf of a married lesbian couple.
All the lawsuits cited the constitutional revision argument, and two of them asked the court to block Proposition 8 from taking effect while the legal cases were pending.
"The court must hold that California may not issue licenses to non-gay couples because if it does it would be violating the equal protection clause," Allred said at a news conference.
In addition to going to court, gay rights advocates sought to assure about 18,000 same-sex couples that their marriages will remain valid.
The groups cited comments by Atty. Gen. Jerry Brown, who has said the initiative was not retroactive. If the marriages are challenged in court, that case too would go to the California Supreme Court. Experts differ on whether the law would protect the marriages.