Here's the thing. As an educator who has worked at two Christian institutions, I can tell you that many educators at relatively conservative schools do an excellent job of challenging our own presuppositions; those ideas that are taken-for-granted-and-never-adequately-questioned by conservative communities. These ideas might relate to gender, politics, theology, sexuality, economics, race and ethnicity, but they are interrogated, and when conservative students want to state their opinions with a belligerent dose of ignorant arrogance, they are asked to think deeply, see the other side of things, etc. Granted, conservative ideas may be given strong social and argumentative support in the end, but they aren't allowed to go unchallenged. I've been less-sure that this happens on the left. A rash of articles, including this one in the NYTimes, indicates that conservatives are nearly as barred from state-funded higher-education as atheists would be from private-Christian higher-education.
Now, recently I have seen a few articles indicating that somewhere on the left is some introspection about its own exclusions and presuppositions, the kind of reflexive scholarship that pomo sociologist Pierre Bourdieu would have considered essential.
Here's a sampling (a lot of this is from the world of social science):
At the center of it is Jonathan Haidt's research, now well represented at his Heterodox Academy site. There's a lot of content there, but you might also want to watch his Ted Talk below.
And of course there is the recent scrutiny of free-speech limits in higher-ed and the coddling of students so they don't have to face disagreeable disagreements. This is now a contested narrative (of course, and why not?), but I don't find the contestations very logical or as data-driven as Haidt piece below and for anecdotal power, check out the Vox piece.
including another "Haidt piece"