SAN FRANCISCO -- Within minutes of Tuesday's announcement by the state Supreme Court ruling that it would uphold Prop. 8 and California's ban on gay marriage, two leading political groups launched a statewide campaign vowing to repeal the controversial ballot measure.

Voting 6-1 with Justice Carlos Moreno dissenting, the court majority reasoned that since the state already provides same-sex couples the same legal protections that opposite-gendered couples enjoy, there was no legal reason to overturn the voters' desire to make a semantic distinction of who can legally apply the word "married" to their relationship and who cannot. The panel, likewise, rejected arguments that the proposition itself represented an illegal "revision" (as versus an "amendment") of the state's constitution. Actual revisions of the constitution cannot be made via the ballot box.

The panel also ruled that the 18,000 same-sex marriage licenses that have been issued in California since its previous May 2008 ruling which legalized gay marriage will remain valid.

The decision wasn't exactly unexpected by two young but powerful political groups, Equality California and Courage Campaign, who said Tuesday that they would immediately begin work to overturn Prop. 8 by qualifying another voter initiative to appear on the 2010 general election ballot.

"Despite today's setback, Equality California is committed to restoring the freedom to marry. We believe, as do the majority of our members, that 2010 is the best time to return to the ballot to repeal Prop. 8. We must take full advantage of the momentum and commitment people now have to do the work required on the ground. However, we will make the final decision on when to return in collaboration with our coalition partners and allies throughout the state," Marc Solomon, Equality California's marriage director, said in a statement. "We have already launched a mobilization campaign to reach more than 300,000 Californians in the next 100 days in places where we need the most movement - Los Angeles County, San Diego, Orange County, the Inland Empire, the Central Valley and Sacramento, and over the coming weeks we will expand our efforts with our partners and tens of thousands of volunteers."

Courage Campaign Founder Rick Jacobs said that shortly after the court issued its ruling, the group began broadcasting this commercial in TV markets across the state.

"Last week, we asked our members to vote on which year -- 2010 or 2012 -- the Courage Campaign should support going back to the ballot to restore marriage equality. The response was overwhelming -- 82.5% support a 2010 ballot measure," said Jacobs. "As a result, the Courage Campaign is announcing today its strong support for a 2010 initiative, while respecting that partner organizations are still discussing and deliberating this very important question. While we were hoping the Court would rule in favor of equality, we have been building the infrastructure to win marriage equality rights at the ballot box. Our members are ready to do the hard work needed to win."

To read the actual text of the court's decision, go here. The case is called Strauss v. Horton, No. S168047.

Follow Jeff Mitchell's Bay Area political journalism at BAPolitix.org