After the debate, a young black woman accosted me indignantly. Ninety-plus percent of black blood is shed by black hands? What about all the victims of white supremacists? Hadn't I heard of lynching? Hadn't I heard of James Byrd, who died so horribly in Jasper, Texas? When I assured her that Byrd's murder by whites was utterly untypical of most black homicide, she was dubious. So I asked for an e-mail address, and promised to send her a link to the FBI's violent-crime statistics. I thought of that young woman when I read recently about James Ford Seale, the former...