Mark William Pocan is an American politician and businessman serving as the U.S. representative from Wisconsin's 2nd congressional district since 2013. The district is based in the state capital, Madison. A member of the Democratic Party, Pocan is co-chair of the Congressional LGBT Equality Caucus and chair emeritus of the Congressional Progressive Caucus. From 1999 to 2013 he served as a member of the Wisconsin State Assembly, representing the 78th district, succeeding Tammy Baldwin there, whom he also replaced in the House when Baldwin was elected to the U.S. Senate.