MOSCOW (Sputnik) — A vocal critic of US foreign and domestic policy and the only lawmaker serving as an independent who caucuses with the Democrats, Sanders was born on September 8, 1941, in Brooklyn, New York, to Polish parents of Jewish descent.
His father, Eli Sanders, immigrated from Poland after witnessing family members falling victim to the Holocaust in World War II. Sanders' mother, Dorothy Glassberg, was born in the United States to Polish Jewish immigrants.
After finishing James Madison High School and spending a year in Brooklyn College, Sanders transferred to the University of Chicago, where he graduated in 1964 with a Bachelor of Arts in political science.
The presidential hopeful then moved to Vermont, where he worked as a filmmaker, carpenter and held other jobs before being elected mayor of Burlington, the state's largest city, in 1981. Sanders defeated six-term Mayor Gordon Paquette by an edge of 10 votes.
Sanders' mayoral tenure ended in 1989, after which he started a teaching career at Harvard University's Kennedy School of Government and at Hamilton College in Clinton, New York, the following year. He taught political science in both schools.
In 1990, Sanders ran for congressional office after losing to Peter Smith in 1988, and became the first lawmaker unaligned with any of the two major political parties since 1951.
The 73-year-old senator represented Vermont in the US House of Representatives from 1991 to 2007. Vermont is one of seven US states with only one member in the lower legislature.
Sanders was elected Vermont's junior Senator in 2007 and won reelection in 2012. His second term, where he also chairs the Committee on Veterans' Affairs, ends on January 3, 2019.
He lives in Burlington with wife Jane O'Meara Driscoll and has four children and seven grandchildren.
According to local media reports, Sanders explains his decision to run on a Democratic ticket with the entrenchment of a two-party system in US political history and the difficulty of third-party candidates to get on the ballot in all 50 states.