State politicians still are hammering out differences over the proposed Global Warming Solutions Act. If passed, it is likely to play a role in November's vote for governor and in national politics for years to come.

Schwarzenegger -- branded "very green for a Republican" by the conservation group Sierra Club -- became an overnight hero for environmentalists a year ago by setting a goal to cut California's emissions to 1990 levels by 2020.

More recently, he accused fellow Republicans in Washington of lacking leadership on the environment as he signed a global warming accord with British Prime Minister Tony Blair.

"We have a pretty brave governor who feels we should take the lead," said Linda Adams, a Democrat Schwarzenegger chose to run California's Environmental Protection Agency.

The Democrats say their bill gives the governor's 2020 target "teeth" with an enforceable cap on emissions and mandatory reporting for top polluters like energy companies.

If Schwarzenegger vetoes the bill because he wants a more business-friendly version, then the Democrats can use it against him in his reelection bid.

"Given that he has staked a large part of his reelection plea on his environmental record, I don't think he is in a position to veto this bill," said Bill Magavern of the Sierra Club in Sacramento.

Schwarzenegger practiced his balancing act while campaigning on Wednesday by saying the bill will be a "compromised version."

"Some environmentalists will say 'this is not perfect' and there will be other people in the business community who will say 'this is not perfect'."

'CHANCES VERY HIGH'

California is an environment-savvy state where being green wins votes. But it is also the world's 12th largest emitter of heat-trapping gases like carbon dioxide. It faces environmental and health disasters with warmer temperatures.

Meanwhile, the population is projected to grow from 35 million today to 55 million in 2050.

The California Chamber of Commerce and business groups say the global warming bill is bad for the economy because it will drive up energy prices and send companies running to less regulated places -- similar arguments used by Bush to pull out of the 160-nation Kyoto Protocol to reduce global warming.

EPA secretary Adams is pushing for a more market-based bill to give business tools to meet goals with "no intent to let any sector or company off the hook."

She believes "chances are very high" Democrats will pass a bill the governor can sign by the end of session on Aug. 31.

Bill co-sponsor and Assembly Speaker Fabian Nunez, who is working for the election of Schwarzenegger's opponent Phil Angelides, denied playing politics with the environment by putting the incumbent on the spot before the election.

"We will send a bill he can sign and we want to champion it across the country," said Nunez, who predicted no Republican member of the California legislature would vote in favor. And that momentum, Nunez said, could help the Democrats in 2008.

"I think the 2008 presidential election will be won or lost on environmental degradation and new thinking on the environment," said Nunez.