evidence: Senator Bernie Sanders has enjoyed a remarkably long career as the ultimate political outsider. His signature message of income inequality, delivered with a metronomic, almost numbing consistency, has often seemed like the only thing one needed to know about him—that is, until he surged to the forefront of the 2020 Democratic field. Now, just days before a slew of wildly consequential primaries from South Carolina on Saturday to California and Texas and beyond on Super Tuesday, people suddenly are discovering or revisiting with a new interest a trove of revealing Bernie-ana. What do voters need to know? Here, culled from books, extensive media coverage and the archives of POLITICO Magazine, is a quick primer on the life of Bernard Sanders, born on September 8, 1941, in Brooklyn, New York, the son of a Polish immigrant, a democratic socialist who also happens to be a millionaire, and the leader of a progressive movement that has convulsed a party with which he long has battled from inside and out. [...] He started a business producing low-budget filmstrips about Vermont and New England history that he sold to schools. He made a 30-minute documentary on Eugene Debs, a prominent labor organizer in the early 1900s and the five-time presidential candidate of the Socialist Party of America—whom Sanders has cited as a hero.