I dislike being the only one who's willing to say this, but the discourses of white nationalists, misogynists, homophobes, religious fanatics and those who seek the destruction of the living planet should NOT be tolerated. 

The groups that practice these discourses are still around and they have a long, sad history: of oppressing and killing people of color, women and gays, of poisoning our water and air, disrupting the climate, destroying biodiversity and ecosystems, and of rationalizing extinctions as good for business. 

To discourage those discourses because of their prior history is not "censorship"; it's merely good sense. Those who don't learn history's lesson must repeat them. Your right to swing your fist ends at my nose. Your right to cry "Fire!" in a crowded theater is not protected by the Constitutions, etc. 

Pluralism does not mean that racism, religious fanaticism and ecocide are treated equally with all other ideologies and interests.