Robert Mercer, Bannon Patron, Is Leaving Helm of $50 Billion Hedge Fundbr “We do not consider the personal political opinions and private activities of individual employees when making decisions.”br Steve Yoakum, executive director for Public School Retirement System of Missouri, another Renaissance investor,br said the furor over Mr. Mercer was a “manufactured issue.” He said performance trumped anything else.br Robert Mercer, a billionaire investor and top financial backer of conservative causes, is stepping down as co-chief executive of Renaissancebr Technologies, as the giant hedge fund faces a backlash from some clients who resent Mr. Mercer’s embrace of polarizing political figures.br The retirement fund for Baltimore’s police and firefighters, for example, last week asked to refund all of the $33br million it had invested in Renaissance, said David A. Randall, the retirement fund’s deputy executive director.br In letters to investors and to Renaissance staff on Thursday morning, Mr. Mercerbr said he would step down as co-chief executive and as a board member on Jan. 1.br Discomfort with Mr. Mercer’s political activism — including protests aimed at university endowments, foundationsbr and pension funds with money invested in Renaissance — has showed signs of taking a small but growing toll.