A recent piece at Inside Higher Education really has 'em going. The editor notes that it drew the most comments of any piece last month by far.
The article focuses on a survey conducted by two economists, who conclude that Republican professors tend be tougher graders than their Democratic colleagues, who by contrast are more "egalitarian." Like a number of posters, I had my doubts about the study's methodology, and wondered how it was possible to correlate party affiliation and grading policy, given so many fudge factors that probably defy quantification. I also couldn't suppress a smile at the wry observation of one poster who noted that there must have been at least five GOP professors in the sample. Read the piece itself, but don't miss the comments thread.
There are some useful responses, but a lot more of the huffing, puffing high dudgeon that illustrates why academics can make such perfect foils.