Vermont Sen. Bernie Sanders announced his bid for re-election Monday, seeking to secure his fourth term in the U.S. Senate. The 82-year-old Independent previously served 16 years as a Democrat in the House of Representatives. Prior to that, Sanders was Mayor of Burlington from 1981-1989. In 2007, he was elected to the U.S. Senate. “I have been and will be, if reelected, in a strong position to provide the kind of help the Vermonters need in these difficult times,” Sanders said in his announcement video. “We have made important progress addressing some serious, serious challenges.” Touting vict…