It's not legally self defense because a baton isnt a deadly weapon nor is it possible to tell who the initial aggressor was. Also that was clearly a street fight and both parties were intentionally aggressors and either one had the ability to flee but decided not to on personal reasons. He'll probably be sued up the ass instead of arrested. Last I checked brain damage is pretty expensive so that white supremacists guy will probably have his life ruined anyways by the million dollar settlement he's gonna have to make in court