United Auto Workers President Shawn Fain delivered a fiery speech at a rally for Democratic presidential nominee Kamala Harris and slammed Republican presidential nominee Donald Trump as the crowd erupted into chants of “He’s a scab!” Fain, whose union represents more than 1 million auto workers, greeted the raucous crowd in Detroit saying the election revolves around one question: “Which side are you on?” “This is a simple question because on one side, you got a billionaire that serves himself and his billionaire buddies,” he said, to boos. “He lies, he cheats and he steals his way to the top…