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.
When the general society is intolerant of nazis, they are not usually calling for nazis to be killed or harmed.
And why aren’t we doing that? They’re literally Nazis?
If ten people knowingly sit down to a meal with a Nazi, you have 11 Nazis.