Or ignoring the fact that these same institutions of higher learning are promoting policies from one side and not another?
No argument, but I do think the reasons matter. I would argue that tertiary education has been typically more liberal than the society in which is is embedded since the time of the Greeks.
There is no left-wing cabal of Public Universities around the nation, run and funded by George Soros, which ensures that conservatism is under-represented in academia. It is a result of the expected promotion of the ideas and notions of the faculty employed therein, from the adjunct professors to the Dean. And to be clear, we really are only talking about a classic Liberal Arts (see? right there in the title
) education. As a STEM major, I never got a whiff of the political leanings of my professors because they were teaching math, physics, chemistry, electronics, and evolution (wink, wink).
There's a reason for the saying "If you're not a liberal at 20 you have no heart, and if you're not a conservative by 40 you have no brain". Young people are passionate about things that have a liberal bias, and young people are the primary university population. Is it really surprising to see their goals and aspirations reflected in the culture? Expanding our knowledge base is frequently an inherently anti-conservative exercise insofar as it upends the status quo.
If you want more representation of conservative idealogy, then you have to graduate more professors and grad students who are so inclined. In fact, you already have them, although they tend to gravitate more towards the private and religious institutions than the public universities.
I look at it like the gender problem in STEM. Folks who want equal female representation in STEM are making the fallacy that equality only comes when there's a 50/50 split in representation. What if more men want to develop micro-electronics than women? Is that bias? Would forcing an equivalency then not be both unnatural and unwise?
Anyway, just a long rant to say that the liberal bias in education does not surprise me any more than the conservative bias in religion. Those things just go together like peanut butter and jelly.