You should take the time to read this analysis:
In this article I offer new evidence about something readers of Academic Questions already know: The political registration of full-time, Ph.D.-holding professors in top-tier liberal arts colleges is overwhelmingly Democratic. Indeed, faculty political affiliations at 39 percent of the colleges in my sample are Republican free—having zero Republicans. The political registration in most of the remaining 61 percent, with a few important exceptions, is slightly more than zero percent but nevertheless absurdly skewed against Republican affiliation and in favor of Democratic affiliation. Thus, 78.2 percent of the academic departments in my sample have either zero Republicans, or so few as to make no difference.
Interestingly enough, the Extreme Bias is found in fields outside of the hard sciences:
Some STEM fields come close to the baseline national average of 1.6:1; potentially ideologically linked fields, especially the interdisciplinary studies fields, do not. Thus, the D:R ratio for engineering is 1.6:1 while for the interdisciplinary studies fields it is 108:0.
This bias outside of the STEM fields is so extreme that the default assumption concerning these non-STEM fields should be skepticism. That is, unless I have good, independent reason to think otherwise, my working assumptions about social scientists and other PhD’s from the humanities is that they are not true scholars; they are highly skilled ideologues, trained through intellectual inbreeding where peer review becomes more akin to the encouragement of ideological purity rather than truth.
There is more to flesh out from the Extreme Bias in academia when I get the time.