For the better part of three decades, Fred Karger practiced the dark arts of public affairs consultancy, often on the side of corporations and conservative movements.

That makes him an unlikely warrior in the struggle for gay marriage and an especially improbable champion of full disclosure in politics.

But Karger has planted himself at the center of both fights. He has organized boycotts of major donors to Proposition 8 and challenged the Church of Jesus Christ of Latter-day Saints, and as a result finds himself enmeshed in a federal lawsuit in Sacramento over political disclosure.

California's capital is filled with operatives who've morphed in unexpected ways, but Karger's saga is the stuff of a Hollywood script. When I first met him in 1986, I never would have suspected he was gay. Few outside his private circle had a clue.

Fewer still would expect him to be a passionate supporter of same-sex marriage. He likes to quip that he is glad he never wed, figuring he would have been divorced twice by now and writing fat alimony checks. But after tossing out that joke, Karger, always quick witted, turns serious.

"I went through hell growing up," he says. The right to marry, he hopes, might help kids by sending them the message that they would have the same basic rights as others.

"It's our civil rights bill," Karger says.

Karger is no angel. His political past and present is not black and white. Often, he was the color of a chameleon. But now he is leading with his heart, employing the skills he gained as a Republican and corporate operative to seriously mess with foes of same-sex marriage.

Karger has worked for Govs. George Deukmejian and Ronald Reagan, Lt. Gov. Mike Curb. We met in 1986 when I covered the California Supreme Court. The Los Angeles-based consulting firm where Karger worked, the Dolphin Group, was leading the effort to dump three liberal justices, including Chief Justice Rose Elizabeth Bird, who regularly voted to reverse death sentences.

Karger's role was to organize grieving mothers and fathers of children murdered by death-row inmates. In the process, he created the most powerful voice in the campaign that brought down the justices, and established a Republican majority that holds to this day.

Two years later, in 1988, Dolphin and Karger gathered victims of Willie Horton, the murderer who committed a rape while on a furlough from a Massachusetts prison during Michael Dukakis' tenure as governor. Karger used the Horton story to help to thwart Dukakis' presidential bid and elect George H.W. Bush.

All through the 1990s, Karger was one of the main, albeit unseen, operatives in California for Philip Morris, U.S.A. Like a character out of "Thank You for Smoking," the satirical book and movie about a tobacco industry shill, Karger to this day calls the world's largest cigarette maker a great and generous client. It helped pay for his Laguna Beach home with its ocean view.

Karger became expert at shaping "coalitions" and "grassroots movements." Astroturf, it's called.

He would caution people who worked for and with him: Don't make mistakes that would permit the public to get a peek at the true client.

During the 27 years he worked for Dolphin, Karger lived by that credo. Karger felt he could step fully out of the closet only after he retired in 2004.

Lee Stitzenberger, Karger's partner at Dolphin Group and friend, said for years they simply did not discuss the fact that Karger was gay. Certainly, he didn't tell clients.

"His biggest encumbrance was hiding sexual orientation," Stitzenberger said. "I'm sure it was difficult, the cracks people would make, the crude remarks."

Then came Proposition 8, the 2008 initiative that defines marriage as being between a man and woman.

Karger stepped into the fight and did what he knows best. He created an organization, Californians Against Hate. The name belies its size. It was Karger and a few friends. Using the Internet and his knowledge of media and his organizing ability, Karger fanned boycotts of the six- and seven-figure donors to Yes-on-8, including a San Diego convention hotel and a Central Valley health food producer.