Long time reader Ian comments:
A comparison with “the American public” isn’t really appropriate – to even be in the pool where you’re thinking about an academic career, you need to have a college degree. And that population if memory serves, is far more liberal than the population at large. More realistic would be a comparison with the population of people who have graduate degree....
Roughly about ~20% of Americans self-identify as "liberal," and ~40% as conservative. The General Social Survey has a variable POLVIEWS, which asks individuals to assign themselves to a position on a political spectrum, from "extremely liberal" to "extremely conservative," like so: 1 = Extremely liberal 2 = Liberal 3 = Slightly liberal 4 = Moderate 5 = Slightly conservative 6 = Conservative 7 = Extremely conservative So in other words, the higher the integer, the more conservative the individual. The GSS has a variable, EDUCATION, which records the highest level attained. It falls into three classes, high school, bachelor's, and graduate degrees (I assume those who did not complete high school are omitted because they didn't attain an education?). Additionally, it has a 10 word vocabulary test, WORDSUM, which has a 0.71 correlation with general intelligence. I combined those on the interval 0-4 (they got 0 to 4 answers correct on the test), and labeled them "dull." 5-8 I labelled "average. And finally, 9 and 10 I labeled smart (about 20% are dull, 65% average, and 15% smart, in the total data set). Constraining the sample to the year 2000 and later, I produced the following charts:
~9% of the sample have graduate degrees, while 25% have bachelor's degrees. So you aren't really seeing middling educational attainments. There is obviously some tendency toward an increase in the proportion of self-identified liberals at graduate levels of education, but the biggest notable trend is the collapse of self-described "moderates" among the more intelligent or educated cohorts. I sometimes wonder if the vacuousness of political moderation is one reason why the term "centrist" is popular among those who are neither liberal nor conservative, but have a higher socioeconomic status. Long time readers know this fact about the dullness of moderates, but I thought I'd reiterate. It's interesting, if consistent. For what it's worth, I think my own political views are becoming more moderate. But don't confuse correlation with causation!