This twitter thread from the Caves Of Qud devs about how they keep the alt-right out of their game community is worth reading.
@stolas not sure I understood what behavior their CoC banned to keep the alt-right out. It seems the writer assumes it's understood. A shame, as effective ways to keep an online community safe from alt-right and such could be helpful.
@eladhen @stolas A concrete example within today's EU politics would be the frame of "unskiled migrants". It's seemingly harmless, seemingly half true; And regularly used to dehumanise and justify fascist behaviour.
The US equivalent is the "but he was a criminal" you've probably seen way too often.
Then there's of course the racists jokes, and the inflammatatory stuff.
Compare that to the specific example (a specific ingame faction) Stolas added and you will probably notice some pattern.