SAN FRANCISCO -- California voters legally outlawed same-sex marriage when they approved Proposition 8 in November, but the constitutional amendment did not dissolve the unions of 18,000 gay and lesbian couples who wed before the measure took effect, the state Supreme Court ruled today.

The 6-1 decision was issued by the same court that declared a year ago that a state law defining marriage as the union of a man and a woman violated the right to choose one's spouse and discriminated on the basis of sexual orientation.

Prop. 8 undid that ruling. The author of last year's 4-3 decision, Chief Justice Ronald George, said today that the voters were within their rights to approve a constitutional amendment redefining marriage to include only male-female couples.

Justice Carlos Moreno, in a lone dissent, said a majority should not be allowed to deprive a minority of fundamental rights by passing an initiative.

The justices ruled unanimously that Prop. 8 was not retroactive and that gay and lesbian couples who relied on the court's May 2008 ruling to get married before the Nov. 4 election will remain legally wed.

Prop. 8, which declared that only marriage between a man and a woman is valid or recognized in California, passed with a 52 percent majority after an intense and expensive campaign. Sponsors, mainly affiliated with Christian conservative groups, raised nearly $40 million for the measure and opponents more than $45 million - combined, a record for a ballot measure on a social issue anywhere in the nation.

And here's the important part:

The ruling, the court's third major decision on same-sex marriage in five years, may be the last word from the state's legal system on the issue. But the matter is far from settled in the political arena. Gay-rights advocates, anticipating the decision, have discussed putting another constitutional amendment on the ballot in 2010 or 2012 to try to repeal Prop. 8.

Indeed. The Courage Campaign has a petition for you to sign calling for the repeal of Prop 8. I think we can count on it being on the next major ballot.