Asked Fred from San Francisco, well Fred; from where I've been, I haven't met any racist bastards, only bastard managers.
Race, is a tool for control, it allows the Dark Manager to create a "we" and "them" scenario. Its essentially like sports where we take sides. One minute we're friends, another, we're mauling at each other because we're on the other side of the field.
It also allows the creation of an "inner circle" for the Dark Manager