KINGSPORT, Tenn. - Matthew Hawn checked his phone to see if the wait was finally over. It had been five months since he was fired for teaching about White privilege at a high school in rural Tennessee. Two months since he had fought to regain his job at an emotional three-day hearing, becoming a symbol of the acrimonious debate over the way race, racism and history should be taught in America's schools. A lifelong resident of Kingsport, Hawn was well aware his liberal views made him an outlier in his overwhelmingly White, mostly conservative community. But that had never mattered...