Bernie Sanders (born September 8, 1941) is an American politician, presidential candidate, and activist who has served as a United States senator for Vermont since 2007, and as the state’s congressman from 1991 to 2007. Before his election to Congress, he was mayor of Burlington, Vermont. Sanders is the longest-serving independent in U.S. congressional history. He has a close relationship with the Democratic Party, having caucused with House and Senate Democrats for most of his congressional career. Sanders self-identifies as a democratic socialist and has been credited with influencing a leftward shift in the Democratic Party after his 2016 presidential campaign. An advocate of social democratic and progressive policies, he is known for his opposition to economic inequality and neoliberalism.