This thread has been moved to The Political Arena by zeke. We all knew it was going to get there eventually.
Karl Popper's "Paradox of Tolerance". If we tolerate intolerance, intolerance will flourish. In other words: if a society is tolerant without limit, its ability to be tolerant is eventually destroyed by the intolerant. Tolerating bigotry allows bigotry to spread. Exclusion isn't always a dirty word. Tell your local Nazi to F off today.