Someone who believes in a totalitarian state rule aby a supreme leader (dictator) who treats people harshly for their own sucess. The dictators are invariable rich older men who have secret police and ure guerilla tatics to suppress the populus. They are mean, evil, racists who believe they are better thatn others.
Hitler - use Nazi sympathisers as "police" and intended to wipe out Jew as believed wrongly that he was more important and better than them. Treated people badly, used malicious propaganda.