After a 12-day trial that included testimony by gay and lesbian couples and experts on the history and purpose of marriage, Walker ruled that Prop. 8 discriminated on the basis of sexual orientation and gender and did not benefit heterosexual spouses or the marital institution.

The measure's sponsors have asked a federal appeals court to overturn the ruling, but the court has questioned whether the sponsors have legal standing - the right to represent the state's interests - after then-Gov. Arnold Schwarzenegger and Attorney General Jerry Brown declined to appeal.

Walker first raised that issue in August, citing a U.S. Supreme Court decision that expressed doubt about whether sponsors of an initiative can stand in for state officials. But he said Wednesday he'd prefer to see the appeals court decide whether Prop. 8 is unconstitutional.

If Prop. 8 is invalidated because no one has the standing to defend it, he said, it will leave "a sense of the issue not having been resolved."