Nobody here said that it's primarily a leftward bias.

True, but the things Nornagest was complaining about could all be at-least-kinda-credibly claimed to have a leftward bias, and could not be at all credibly claimed to have a rightward bias.

Of course, as you say, there's a lot more to politics (and putative biases in academia) than left versus right, but it's a useful approximation.

Lest I be misunderstood, I will add that I too have a leftward bias, and I do not in fact think anyone would get a better education, or find better researchers, by choosing a right-leaning place (except that there are some places that happen both to be good and to have a rightward slant, I think largely by coincidence, and if you pick one of them then you win). And I share (what I take to be) your disapproval of attempts to manipulate public opinion by funding academics with a particular political bent.