The politician describes himself as a democratic socialist. From 1981 to 1989, he served as the mayor of Burlington, Vermont. He was also a member of the U.S. House of Representatives. Unaffiliated with any political party, he is the Senate’s longest-serving Independent. Although he was an Independent, Sanders was nominated as a Democrat in the U.S. presidential elections of 2016 and 2020. He won 23 primaries and caucuses while being an Independent. Sanders was part of the Democratic leadership team in the Senate.