Marty Beil, who as the longtime leader of the union that represented Wisconsin’s state employees was at the center of the fight in 2011 against Gov. Scott Walker’s proposal that effectively ended collective bargaining for most public workers, died on Thursday at his home in Mazomanie, Wis. He was 68. The cause has not been determined, his sister, Mickey Beil, said. To many, Mr. Beil was the face of the state employees union, an outspoken advocate of workers’ rights for more than 40 years. In the 2011 fight with Mr. Walker that he ultimately lost, Mr. Beil helped organize protests...