Liberalism Is an Affinity for Things that Are New and Trendy
Hoisted from Comments: Bruce Bartlet:
Grasping Reality with Both Hands: Brad DeLong's Semi-Daily Journal: Under the best of circumstances, getting a tenured position at an elite university is very hard. Because you can't get rid of someone with tenure and may be stuck with them as a colleague for decades, it stands to reason that the process of choosing someone for such a position is going to be very intense. For the same reason, the choice is not entirely meritocratic--elite universities don't choose the best scholars as professors any more than they choose the best applicants as students. There are a lot of factors that go into a hiring decision that don't favor conservatives and go beyond simple ideology.
Just to mention one area, conservatives have a tendancy to choose sub-disciplines within academic fields that are not very fashionable. For example, in political science, conservatives tend to gravitate toward political theory--a field that has been out of fashion since at least the 1960s. In history, conservatives often excel at military and diplomatic history--again, fields that have been out of fashion for decades.
One of the basic elements of liberalism is a greater affinity for things that are new and trendy. For conservatives, it is the opposite--an affinity for the familiar, the tried and true. This means that conservatives are always going to be behind the curve in any field where changing fashion is a key to advancement.