Wiki - The paradox of tolerance states that if a society is tolerant without limit, its ability to be tolerant is eventually ceased or destroyed by the intolerant. Karl Popper described it as the seemingly self-contradictory idea that in order to maintain a tolerant society, the society must retain the right to be intolerant of intolerance.
I dislike the framing of this, specifically:
“When we extend tolerance to those who are openly intolerant the tolerant ones end up being destroyed”
Implies that the intolerant are guarenteed victory. I vehemently disagree that this is true, and therefore would argue tolerating the bad actors is often a necessary evil to ensure that good actors are not unjustly censored. The risk of ‘another hitler’ is accepted this way of course but unless we as a society can demonstrate (if at all) that risk would be mitigated by the censorship of hate speech we have no good cause.