'Say, a high school refusing to hire someone based on their liberal beliefs (say, transgender people being able to use the bathroom they identify as)? After all

'Say, a high school refusing to hire someone based on their liberal beliefs (say, transgender people being able to use the bathroom they identify as)? After all, it's very possible for the school to say "nothing productive can come from sharing a department with them".' Yes, the school could say that, but they might not be right (a case of a valid but unsound argument). In any case I view that hypothetical (barring a teacher based on what they think about transgender bathroom priveleges) as preferable to, say, barring a teacher based on something they had no say on such as their skin color (although, as I must continue to point out-- that doesn't mean it's not also preferable to not discriminate at all!)