Under intense pressure from both sides in the debate over same-sex marriage, the California Supreme Court will hear arguments Thursday on the ballot initiative passed by voters last November that outlawed such unions.


For opponents of the measure, Proposition 8, the three-hour hearing is a critical legal test. But it is also, they say, a prime moment to rally their forces and demonstrate resilience after a stinging election loss that many among them believe could have been avoided.

“It’s a need for the community to show that we will not be passive participants to our own struggle,” said Kate Kendell, executive director of the National Center for Lesbian Rights. “I think it goes to the heart of what we’ve seen since Nov. 5, and what we’ve come to appreciate as the critical importance of everyone stepping up and stepping out.”

To that end, Thursday’s hearing is being treated by some activists as a combination of election night and Super Bowl. In San Francisco, for example, Proposition 8 opponents have erected a Jumbotron screen in front of the courthouse for spectators unable to squeeze into the courtroom.

“This is our lives on the line,” said Molly McKay, media director of the volunteer group Marriage Equality USA. “We don’t want them to have to worry about getting in.”

Ms. McKay’s organization, one of several grass-roots groups that have taken a larger role in the debate on same-sex marriage since the election loss, also organized candlelight vigils around the state for Wednesday night. But more established gay rights groups like Equality California are using the hearing as a rallying point as well, having begun a television campaign on Tuesday with advertisements depicting the quest for same-sex marriage as part of a long-term civil rights campaign.

Supporters of Proposition 8, meanwhile, have taken a quieter tack. Frank Schubert, the campaign manager for Protect Marriage, the leading group behind the initiative, said supporters held a day of prayer on Sunday, asking that the justices “be granted wisdom and for our opponents to understand that our support of Proposition 8 is to affirm traditional marriage, not denigrate gays.”

Mr. Schubert also said his side had asked that supporters who choose to show up outside the courthouse on Thursday not provoke confrontations and not carry signs unless they bear positive language.

While the fall campaign was heated — and expensive, with each side spending more than $40 million — the hearing is bound to seem somewhat anticlimactic to many. The court will only hear oral arguments on Thursday, and has 90 days to come to a decision.