Billionaire Tom Steyer exploring run for Barbara Boxer 's seat . `` Californians deserve a strong voice in Washington and I have never been afraid to speak up , which is why I am seriously considering running for the United States Senate in 2016 . '' The billionaire environmentalist is considering a bid to unseat the California Democrat in 2018, according to sources familiar with his plans. Lieutenant Governor Gavin Newsom is out of the race .
Billionaire Tom Steyer exploring run for Barbara Boxer 's seat . The billionaire environmentalist is considering a bid to unseat the California Democrat in 2018, according to sources familiar with his plans. Lieutenant Governor Gavin Newsom is out of the race .