Blac Chyna says she always knew she'd be vindicated in her hairdresser knife case, 'cause the lady was simply thirsty for the spotlight -- but she ain't gonna drink from Chyna's fountain. Also the back-to-back Democratic debates -- which will feature candidates of Black, Hispanic, Samoan, Indian and Asian descent -- will be a major test for those trying to tackle the issue of diversity ... in the lighting department.