In July, Steyer hired Gil Duran, a former top spokesman for Brown, as a spokesman on California issues. Duran minimized his role, saying in an interview that Steyer had effective media- outreach aides already.

Last week, in a letter he made public, Steyer challenged Chevron’s Watson to an open debate on why gas prices in California have risen more than in other states. Chevron spokesman Braden Reddall didn’t say how Watson responded to the challenge, but noted in an e-mail that the company already engages in discussions about gas prices with politicians, regulators and the media.

NextGen Climate Action, Steyer’s super political action committee, has spent $729,000 on lobbying the California government so far this year, compared with about $100,000 in the prior legislative session, according to data from the Secretary of State’s office. Oil and gas interests, led by the Western States Petroleum Association trade group and Chevron, have spent $6.8 million -- including on lobbying against the bill Steyer supports.

Energy-Efficient Retrofits

Californians for Energy Independence says it has evidence that one of Steyer’s businesses, Kilowatt Financial, could make more money if the bill is passed. Steyer is listed as a manager of the limited-liability company in an April 2014 filing with the Secretary of State. Kilowatt makes consumer loans for energy-efficient home renovations and is merging with another lender.

Sabrina Lockhart, spokeswoman for the energy-independence group, said Kilowatt stands to gain from the legislation because the bill mandates the renovations.

“He’s trying to shape policies and he’s trying to benefit financially,” she said.

Steyer’s spokeswoman, Suzanne Henkels, says he stepped down from Kilowatt last year and directed all his green-energy investments into a charitable trust, meaning he won’t profit from the company’s operations.

Keystone Critic

Steyer also was criticized for his opposition to the Keystone XL oil pipeline between Alberta, Canada and Nebraska. The national Republican Party denounced him in a Web posting for opposing the pipeline after Farallon profited from oil and gas investments, and invested in a company proposing a rival pipeline. Steyer still has vowed to back Democratic lawmakers who face attacks for voting against it.