It's pretty simple, isn't it? The far left at Harvard is extremely frustrated with political trends in the U.S. Their votes and activism against Bush were not only completely ineffectual, but they don't even have a Democratic governor in one of the most liberal states in the country. So they pick on the closest thing Harvard has to a powerful right-winger: moderate Democrat and university president Larry Summers, who becomes a stand-in for all evil conservative white men, from Bush on down. The far-left faculty finally participates in a vote that it can win, and experiences cartharsis; that'll teach the world to ignore them! The rest of us shake our heads and wonder: how did these folks ever come to dominate the Harvard faculty?

UPDATE: Here's an interesting post attributing some of the anti-Summers sentiment to anti-Clinton backlash.