>>514078578 (OP)
a) It's not necessarily true, I don't think every Nazi wants billions genocided. They don't even believe the first Holocaust happened, so you can't even assume a Nazi wants every Jew dead.
b) By this logic you can kill communists, too. Just going by their own words on social media never mind history they want countless people executed for wrongthink.
Using violence against people because, if in a position of power, they would use violence against their enemies, is untenable. Because everyone uses violence against their enemies. Including Democrats and Republicans. How many people died in the Iraq war? Will we kill every neocon and liberal that supported that? That's the nature of politics. If we go around killing everyone who would impose their vision using violence there'll be nobody left.