Karen Wilkerson : Trayvon Martin case not first Florida killing with racial overtones and no arrest . Black men killed for trying to vote , black churches burned to ground , she says . Wilkerson : Florida has been part of the South and its vigilante - based racial justice system . The difference in Martin case is people of all backgrounds are outraged , Wilkerson says .
Isabel Wilkerson : Trayvon Martin case not first Florida killing with racial overtones and no arrest . Black men murdered for trying to vote , black towns burned to ground , she says . Wilkerson : Florida has been part of the South and its vigilante-enforced racial caste system . The difference in Martin case is people of all backgrounds are outraged , Wilkerson says .