In a decision announced moments ago, the court upheld the law but allowed the marriages of nearly 18,000 couples who were married before the measure's approval last November to remain valid. Thousands plan to participate in rallies all over California today in response to the court's ruling.
Eight years ago, California voters approved Proposition 22, which specified in state law that only marriages between a man and a woman are valid in California. But in May 2008, the state Supreme Court ruled the law was unconstitutional because it discriminated against gays, and soon after thousands of couples got married.
Same-sex marriage opponents quickly got Proposition 8 on the November ballot, and it was approved by a margin of 52.5 percent to 47.5 percent.
62-year-old Jeannie Rizzo, who was one of the lead plaintiffs along with her wife, Polly Cooper, said "It's not about whether we get to stay married. Our fight is far from over. I have about 20 years left on this earth, and I'm going to continue to fight for equality every day."