The way to prevent a bar from turning into a Nazi bar is by nipping it in the bud. You need to ignore their reasonable sounding arguments in the moment because their end goals are so terrible. For example, the first Nazi in the bar who is nice to everyone who is getting kicked out might say, “Hey I’m not doing anything wrong!”. However, if you don’t do that, they bring their friends, and friends of friends, and eventually you end up being a Nazi bar.
Online communities function similarly—the moment you let them in the sooner you become a bastion of hate.
Read the Twitter thread.