The New York Times has  one of those stories that seem to appear every six months or so about the dearth of conservatives in academia. Conservatives seem to view this entirely as a problem of academic ideological bias. I certainly think that exists, but it can't explain all or even most of the problem, given that even the hard sciences are overwhelmingly Democratic.

One factor is that conservatives are probably less likely than liberals to choose academia, as Paul Krugman notes:

Ideologies have a real effect on overall life outlook, which has a direct impact on job choices. Military officers are much more conservative than the population at large; so? (And funny how you don’t see opinion pieces screaming “bias” and demanding an effort to redress the imbalance.)

The larger issue, I have argued, is that Republicans don't understand that academia's stampede away from their party is an indictment not of academia but of them:

In recent years, and especially under George W. Bush, Republicans have cultivated anti-intellectualism. Remember how Bush in 2000 ridiculed Al Gore for using all them big numbers?
That's not just a campaign ploy. It's how Republicans govern these days. Last summer, my colleague Frank Foer wrote a cover story in the New Republic detailing the way the Bush administration had disdained the advice of experts. And not liberal experts, either. These were Republican-appointed wonks whose know-how on topics such as global warming, the national debt and occupying Iraq were systematically ignored. Bush prefers to follow his gut.
In the world of academia, that's about the nastiest thing you can say about somebody. Bush's supporters consider it a compliment. "Republicans, from Reagan to Bush, admire leaders who are straight-talking men of faith. The Republican leader doesn't have to be book smart," wrote conservative New York Times columnist David Brooks a week before the election. "Democrats, on the other hand, are more apt to emphasize ... being knowledgeable and thoughtful. They value leaders who see complexities, who possess the virtues of the well-educated."
It so happens that, in other columns, Brooks has blamed the dearth of conservative professors on ideological discrimination. In fact, the GOP is just being rejected by those who not only prefer their leaders to think complexly but are complex thinkers themselves. There's a problem with this picture, all right, but it doesn't lie with academia.

Conservatives like to present this as an issue of Marxist English professors, but the reality is that scientists, mathematicians, and people trained in rigorous thinking of all kinds are overwhelmingly rejecting them.