One of the great errors in political thinking is mistaking bad excess with bad categories.
At first blush this is just a fancy way of rephrasing one of the least profound insights one can offer: Don’t let a few bad apples lead to defunding the police, the FBI, whatever. Don’t let a few racist white people drive you to blather, “Yes, ALL white people are racist.”
But the bad apple thing is merely one facet of what I’m talking about. People often think that the extreme expression of a concept reveals the “true nature” of a concept. Horrible things are done in the name of nationalism, therefore “true” nationalism is horrible. Terrible things are done in the name of socialism, therefore “true” socialism is terrible. There’s no -ism you can’t do this with. Whether it’s slippery slopeism or the hasty generalization fallacy or a half-dozen other logical fallacies, we have a tendency to think that the plural of anecdote is data, that if A happens Z must inevitably happen, and that the most pure and extreme form of a phenomenon or concept is its truest self.