The race to succeed retiring California Senator Barbara Boxer is going through a primary of sorts - the kind that doesn't involve voters.
Billionaire environmental activist Tom Steyer is the latest to float his candidacy. He's making calls to prominent Democrats to gauge their interest ... and says he expects to decide soon if he'll enter the campaign.
Steyer's announcement Tuesday came shortly after state Attorney General Kamala Harris became the first Democratic candidate to declare she'll run.
Former Los Angeles Mayor Antonio Villaraigosa is also considering a run.
Steyer is a 57-year-old former hedge fund manager who's poured his fortune into political action committees supporting Democrats and ballot measures fighting climate change.
The 50-year-old Harris is a former two-term San Francisco district attorney. Her quick entry into the race appears designed to discourage potential challengers and give her a jump-start on fundraising.
-The Associated Press and Capital Public Radio Staff