The images that have graced Dick Gregory’s obituaries show the comic-turned-activist with a long white beard and a weathered face, educating crowds about the killing of Trayvon Martin or police brutality. But before his transformation into an activist, Gregory was a man on a stage in front of a sometimes-hostile crowd, making acerbic, insightful jokes about race, segregation and the civil rights movement that still resonate half a century later. Gregory died Saturday at age 84.