Hedge fund manager Tom Steyer, the billionaire Democrat who has spent considerable cash on environmental causes and candidates, will not run for Senate in California, he announced Thursday .  

Steyer openly mulled entering the race to replace retiring Sen. Barbara Boxer, D-Calif., but he passed on it, saying he decided he could have the most impact on environmental issues not in the Senate, but back home in California.  

“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,” Steyer said in an entry on the Huffington Post .  

California Attorney General Kamala Harris announced her bid for the seat earlier this month. She quickly picked up the endorsement of top Democrats, including Sens. Elizabeth Warren, Kirsten Gillibrand and Cory Booker.  

Many Democrats view Harris as the front-runner in the race, but other candidates are still weighing bids.  

They include former Los Angeles Mayor Antonio Villaraigosa and several House Democrats, including Reps. Xavier Becerra, John Garamendi, Raul Ruiz, Loretta Sanchez and Jackie Speier.  

Democratic Rep. Adam Schiff, who represents a Los Angeles-area district, announced Thursday he is also considering a bid.  

“Since Senator Boxer announced her retirement, I have been encouraged by many Californians to run for her seat in 2016,” Schiff said in a statement. “As the opportunity to run for a California senate seat comes around very seldom and I would relish the chance to serve the entire state, I am giving the matter serious consideration.”  

In California, all candidates run on the same primary ballot, with the two highest vote recipients, regardless of party, advancing to the general election. It’s possible two Democrats will make it to the general election, ensuring the seat stays in Democratic hands but also prolonging what will already be an expensive primary race for the seat.  

Steyer would almost certainly have self-funded his campaign if he ran. And while that would give him the necessary funds to run a race projected to cost around $100 million, self-funding candidates have a poor track record in California.  

Several Republicans have spent millions of their own cash on unsuccessful statewide bids, including former Hewlett-Packard CEO Carly Fiorina, current Hewlett-Packard CEO Meg Whitman and former Rep. Michael Huffington, the former spouse of Huffington Post co-founder Arianna Huffington.  

Democrt Al Checchi, then co-chairman of Northwest Airlines, also spent tens of millions of his personal fortune in an unsuccessful run for governor in California in 1998.  

California’s Senate contest is rated Safe Democrat by the Rothenberg & Gonzales Political Report/Roll Call.  

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