Tom Steyer won’t run for Senate

The former hedge fund manager made his announcement in a blog for the Huffington Post, saying he felt his best chances at leveraging influence on climate change policy came as an outsider rather than in Washington.

“Given the imperative of electing a Democratic president — along with my passion for our state — I believe my work right now should not be in our nation’s capital but here at home in California, and in states around the country where we can make a difference,” said Steyer, a registered Democrat.

Steyer was the country’s largest individual donor in the 2014 election, spending $74 million largely through his NextGen Climate Action super PAC. He tried to elevate Democratic candidates at the state and national levels who supported efforts to reduce greenhouse gas emissions that scientists say warm the planet.

Steyer’s results were mixed, at best: Two of his preferred Senate candidates won while two lost, and just one of three gubernatorial candidates he backed won his contest.

While that spending earned him a bit of name recognition, Steyer was facing a crowded field in the race to fill the seat being vacated by Democratic Sen. Barbara Boxer. Democratic California Attorney General Kamala Harris has emerged as the front runner, and former Los Angeles Mayor Antonio Villaraigosa is also in the running.

Steyer’s advocacy has long been linked to a potential run for political office, and some reports have said he might be interested in running for governor of California.