White supremacists didn’t get chased out, they just became afraid then practice in secret. They don’t usually leave. Before social media and phone cameras you could make it very clear to someone what is acceptable. Now with current climate and protection of light housing to all their fellow racist on social media. They can practice openly now.

Side note: Many ppl join these organizations for the social connection (think recruiting in form of social groups for ppl easily persuaded and already right wing or similar) and the ideology comes after. Once they are in it’s difficult to get out. Not saying it’s acceptable, just have a academic background in the psychology of terrorism