From an e-friend who holds paper on my old spat with Jonathan Chait:

Another installment of “are liberals more empirical?” — see [here] Short story: Richard Sander, a liberal, has published articles with the thesis that black students are ill-served by a system in which affirmative action systematically puts them in schools where they don’t meet the usual qualifications. Sander and other mostly liberal researchers have tried to get data on bar passage rates in California. Several other liberal professors collaborated to oppose and ultimately block them from getting access to the data (note that the blog post refers to Richard Lempert, a professor who elsewhere wrote an entire article in opposition to Sander’s research and now has joined the cause of blocking Sander from getting access to more data).

Update: Chait responds here.