Nazi bar

Etymology
From an anecdote shared by Michael B. Tager (@IamRageSparkle) on Twitter in July 2020. In the multi-tweet thread, Tager recounted visiting a "shitty crustpunk bar", where he saw a patron abruptly expelled. The bartender explained that the man was wearing "iron crosses and stuff", and that he feared such patrons would become regulars and start bringing friends if not promptly kicked out, which would lead him to realize "oh shit, this is a Nazi bar now" only after the unwanted patrons became too "entrenched" to kick out without trouble.

Noun

 * 1)  A space in which bigots or extremists have come to dominate due to a lack of moderation or by moderators wishing to remain neutral or avoid conflict.