Mix together a couple of big oil refiners, an arch-conservative oil tycoon, "green tech" venture capitalists, a former secretary of state and California's far-reaching climate legislation, and stir.

The result is one of the most volatile and expensive political battles of the year.

The issue is Proposition 23, a California referendum that would shelve the state's four-year-old climate legislation until unemployment there falls to 5.5 percent - more than half the current level - which economists agree could take many years. The delay would upend a myriad of solar, wind and low-emission automobile projects.

The referendum has also become a test case about the power of corporate money - mostly from two Texas-based firms - and a measure of how much climate change is sucking wind as a political cause. Fresh off their defeat on a climate bill in Congress, environmentalists and their allies are fighting to prevent their biggest policy success from being rolled back in the country's most "green"-friendly state.

The California legislation would slash greenhouse emissions by 30 percent, limit tailpipe emissions and set targets for utilities' renewable energy use.

A game of big money



One indicator of the emotional charge surrounding the debate was the language Gov. Arnold Schwarzenegger (R) used to attack Prop 23 supporters.

"Does anyone really believe that these companies, out of the goodness of their black oil hearts, are spending millions and millions of dollars to protect jobs?" Schwarzenegger said recently. "This is like Eva Braun writing a kosher cookbook. It's not about jobs at all, ladies and gentlemen. It's about their ability to pollute and thus protect their profits."

The proposition held a slight lead at one point, according to polls, but is now narrowly trailing.

The measure was the brain child of a state legislator, a Sacramento lobbyist who has represented tobacco companies and two oil refiners.

By early October, Valero Energy, the nation's biggest refiner, had poured $4 million into an ad campaign, public records show. Tesoro, the other refiner, has matched that, a company official said. The Koch brothers, who have supported the tea party movement and other conservative causes, added more than $1 million. Other donors brought the total to $16 million.

But Big Oil isn't the only big money in California.

Lined up against the refiners are a group of wealthy fund managers, clean technology investors, environmental groups and onetime Reagan secretary of state George Shultz, who believes that "climate issues are very real" and that Proposition 23 is "a very bad thing."