He worked on his friend Robert Kennedy's presidential campaign in the '60s, and was at the Ambassador Hotel in Los Angeles when Kennedy was assassinated there in 1968. Shattered by the loss, Bobby was drawn to more serious subject matters and began singing protest songs under the name "Bob Darin." Fans who showed up in Vegas to hear the "Mack the Knife" singer were shocked to see him without his toupee, wearing blue jeans instead of his signature tux. They booed him off the stage.