Sometimes it’s “being edgy just for the sake of it isn’t cool. Don’t be an idiot; people fought wars over this.” Students generally respect him, so once they realize he doesn’t play that game, they stop doing it in his classes.

If it’s a specific kind of bigotry, he points out that someone important to him is black/gay/trans/an immigrant/etc, and asks the kid if they’ve even met someone in that group. Most of the time the kid hasn’t and they’re just parroting things they’ve heard at home or online.