So I did some research (the only reason I look at Democrats at all is to pump up my snark on Reddit):

Tom Steyer's campaign is funded by coal and private prisons

In October 2012, Steyer stepped down from his position at Farallon in order to focus on advocating for alternative energy.[16][17] Steyer decided to dispose of his carbon-polluting investments in 2012, although critics say he did not dispose of them quickly enough and noted that the lifespan of the facilities he funded would extend through 2030.[18] A 2014 New York Times article said coal-mining companies that Farallon invested in or lent money to under Steyer had increased their coal production by 70 million tons annually since receiving money from Farallon, and that Steyer remained invested in the Maules Creek coal mine.[18] Prior to Steyer leaving Farallon, a student activist group called UnFarallon criticized the company for investments in companies with anti-environmental policies.[8] In 2016, some critics noted that Farallon had also invested in private prisons while Steyer was leading the hedge fund.[19] According to SEC filings, Steyer was at the helm as the hedge fund purchased nearly $90 million of Corrections Corporation of America stock (5.5% of the company's outstanding shares).[20]