Magerman later criticized Mercer’s support for Trump in a story published in the Wall Street Journal on Feb. 23. Magerman said he had sent an email advising the hedge fund’s general counsel, Carla Porter, and its chief financial officer, Mark Silber, about what he intended to tell the newspaper and was told by Silber that it was permissible under company policy. He was suspended a day later, he said.

Poker Tournament

On April 20, Magerman attended a celebrity poker tournament in New York City, where many Renaissance staffers were present, according to the suit. Magerman told the Wall Street Journal that he attended the event to repair his frayed relationship with the firm, according to an April 28 article.

Rebekah Mercer allegedly confronted Magerman, calling him "pond scum" and saying karma "is a bitch," according to the complaint.

Magerman was fired April 29, according to the suit. Magerman seeks "substantial damages," his lawyer said.

Renaissance’s employee handbook bars workers from disparaging the hedge fund or any of its workers, though such policies are "illegal and unenforceable," according to the complaint.

Magerman said he designed mathematical and statistical algorithms to direct Renaissance’s investment decisions on international financial markets, resulting in billions of dollars in revenue for the hedge fund.

Based in East Setauket, New York, Renaissance was started in 1982 by Jim Simons, a former military code cracker. He stepped away from the business at the end of 2009. Mercer and Brown took over the following year.

Private sector employees are generally not protected from political discrimination, said Robert Young, an employment lawyer with Bowditch & Dewey LLP in Boston. But Magerman may have a claim if he can prove he was retaliated against for complaining about race bias by Mercer.

"That may be the more viable of the two claims because there does seem to be a connection between objecting to those comments and termination,” Young, who isn’t involved in the case, said in a phone call.