Palácio do Planalto from Brasilia, Brasil · CC BY 2.0

A Brooklyn-born democratic socialist who spent decades arguing that American politics had drifted too far from the New Deal, and lived to see the argument go mainstream. Elected mayor of Burlington, Vermont in 1981 on a shoestring campaign, he moved to Congress in 1990 and became the longest-serving independent in congressional history, caucusing with Democrats without joining them. His 2016 and 2020 presidential runs, built on small donations and a case against income inequality, pulled the party's platform toward positions it had avoided for years.