The Rev. Jesse Jackson’s two presidential runs and his life of activism inspired leaders across generations. Politicians and activists shared tributes after Jackson's death Tuesday and said his message still guides their work. Georgia Sen. Raphael Warnock says Jackson showed him what was possible and pushed him to fight for justice. Jackson’s 1984 and 1988 presidential campaigns led Democrats to open up their primary system. That shift helped former President Barack Obama win two decades later. Jackson also mentored young leaders through his Rainbow PUSH Coalition. Scores of activists, political operatives and members of Congress credited their careers to Jackson.