In this Aug. 5, 2015, file photo, billionaire climate activist Tom Steyer, right, speaks during a news conference with consumer advocate Jamie Court, left, president of Consumer Watchdog in Santa Monica, Calif. (AP Photo/Nick Ut, File) ** FILE **
Billionaire climate activist Tom Steyer, right, speaks during a news conference with consumer advocate Jamie Court, left, president of Consumer Watchdog in Santa Monica, Calif. (AP Photo/Nick Ut, File)
Oregon's controversy has created new questions for billionaire environmental activist Tom Steyer, a major Democratic supporter and bundler for President Obama. (Associated Press)
Environmentalist Tom Steyer speaks to the Center for American Progress’s Second Annual Policy Conference in Washington. (AP Photo/Manuel Balce Ceneta, File)
In this Sept. 5, 2012, file photo, Tom Steyer waves as he walks to the podium to address the Democratic National Convention in Charlotte, N.C. (AP Photo/J. Scott Applewhite, File)
Businessman and liberal billionaire donor Tom Steyer has released several ads attacking Republicans for taking money from the Koch brothers. (Associated Press)
Billionaire financier Tom Steyer (center) is an environmental activist who is spending $100 million to help elect Democrats this fall. He is rallying support for energy taxes that could impact everyday Americans. But when he ran his own hedge fund, Mr. Steyer sought to help wealthy clients legally avoid paying taxes, reports show. (Associated Press)
Businessman Tom Steyer, a former hedge-fund manager turned climate-change hard-liner whose fortune stems in part from investments in the fossil-fuel industry, has pledged to donate $50 million and raise $50 million on behalf of four Democratic Senate and three gubernatorial candidates. (Associated Press)
Businessman Tom Steyer listens during a meeting to announce the launch of a group called Virginians for Clean Government at Virginia Commonwealth University in Richmond, Va., Wednesday, Sept. 25, 2013. While Democrats hammer away at the influence of the Koch brothers, conservatives are swinging back by pointing to the liberal campaign activism and free-spending ways of the wealthy Steyer brothers, Jim and Tom. (Associated Press)