The California Supreme Court upheld the voter-passed marriage amendment, Tuesday, even as it ruled that the tens of thousands of gay marriages performed last year will remain valid.
The justices rejected the agument that the amendment, known as Proposition 8, revised California constitution's equal protection clause so much that it needed the Legislature's approval.
Click play to watch CBN News coverage with reporter Efrem Graham, followed by comments from Peter Sprigg of the Family Research Council.
Since last year, supporters and opponents of gay marriage in California have found themselves on a roller coaster ride.
Last May, the state's high court ruled in favor of same-sex marriage, despite a pending vote on a constitutaional amendment that limited marriage to a man and a woman. Gay couples across the state began to marry the following month.
But in November, voters passed the marriage amendment by a narrow margin. Because Proposition 8 defined marriage as only between one man and one woman, it effectively banned gay marriage.
Supporters on both sides of Prop 8 spent a combined $80 million, making it the country's most expensive ballot measure on a social issue ever.
"We've had a lot of support from people outside the state, as has the other side, because everyone recognizes the huge cultural influence that California has on our country and our country throughout the world," Bishop Salvatore Cordileone, with the Catholic Diocese of Oakland, said.
That influence is what makes today's decision so big.
Gay rights supporters had hoped momentum is on their side, after recent victories in Iowa, Maine, and Vermont. They're planning marches across California tonight to protest the ruling.
But Prop 8 supporters were cautiously optimistic. In March, the court's hearing on the issue showed the justices' skepticism towards the Prop 8 challenge.
"The court seemed to indicate that the position put forth by the challengers of Prop 8 was a radical legal position that they were not going to adopt," Jim Campbell, with the Alliance Defense Fund, said.
Supporters for gay marriage say they won't give up. They'll appeal via the ballot box as early as next year.