Johnathan Chait, writing in the LA Times, makes an argument that I've been trying to make here in bits and pieces:

A few weeks ago, a pair of studies found that Democrats vastly outnumbered Republicans among professors at leading universities. Conservatives gleefully seized upon this to once again flagellate academia for its liberal bias.

Am I the only person who fails to understand why conservatives see this finding as vindication? After all, these studies show that some of the best-educated, most-informed people in the country overwhelmingly reject the GOP. Why is this seen as an indictment of academia, rather than as an indictment of the Republican Party?

Conservatives have a ready answer. The only reason faculties lean so far to the left is that deans, administrators and entire university cultures systematically discriminate against conservatives.

They don't, however, have much evidence to back this up. Mostly, they assume that the leftward tilt is prima facie evidence of anti-conservative discrimination. (Yet, when liberals hold up minority underrepresentation at some institutions as proof of discrimination, conservatives are justifiably skeptical.)

Conservative pundit George Will recently tied the dearth of conservative professors to the quasi-Marxist outlook in African American studies, women's studies and cultural studies... this no doubt makes things hard on prospective conservative academics, not to mention mainstream liberal ones...

...but the rise of fashionable left-wing scholarship can be blamed for only a tiny part of the GOP's problem. The studies showing that academics prefer Democrats to Republicans also show that this preference holds in hard sciences as well as social sciences. Are we to believe that higher education has fallen prey to trendy multiculturalist engineering, or that physics departments everywhere suppress conservative quantum theorists?

Chait then goes on to speculate about possible causes. Most of his column is quite good but I have one small quibble. Chait proposes a possible explanation:

Republicans don't particularly want to be professors. To go into academia — a highly competitive field that does not offer great riches — you have to believe that living the life of the mind is more valuable than making a Wall Street salary. On most issues that offer a choice between having more money in your pocket and having something else — a cleaner environment, universal health insurance, etc. — conservatives tend to prefer the money and liberals tend to prefer the something else. It's not so surprising that the same thinking would extend to career choices.

Generally speaking, tenured jobs at top universities (Caltech, Stanford, MIT) in science/engineering are far better than private sector jobs by any criterion, including money. That these universities show the same leftward tilt disproves the "private sector as a giant vaccum that sucks out all the conservatives" argument.

Also: the high-tech enclaves in the U.S., e.g Silicon Valley, Austin, TX, Route 128 in MA, are the most reliably Democratic areas of the country, giving lie to the notion that private industry engineers and scientists are significantly less likely to be Democrats.

Update: Rich at Beef Always Wins provides a critique. See the comments below for my response.