You and others have left out one of the worst in modern history Pol Pot and the Khmer Rouge. His rule slaughtered as many people if not more. We will never know due to the limited access and or actual willingness of Cambodia's people to speak out. We also have numerous South American "rulers" supported by both sides of the aisle who systematically have been disposing of it's people and indigenous cultures for decades.
Here we have 50% of the population supporting a .gov / administration who has no problem giving it's followers any & everything they want, placating them in to what we have experienced since LBJ's welfare program was instituted. Eventually everyone will either be working for, supported, Or Interned, by the government.