Ambinder, who, before he dove into the muck of political journalism, was the Crimson's police reporter, knows a thing or two about the apparently mean streets of Cambridge:
"What happened to Professor Henry Louis "Skip" Gates, Jr. is hardly unique and in my reporting experience, these clashes tend to involve young white students being strung out by overaggressive cops on generally bogus "disorderly conduct" charges, which is the Cambridge police officer's catch-all charge for "generally just pissing me off and acting holier than thou." Indeed, college kids in Cambridge often showed disrespect for the cops, so it's not surprising that the cops felt disrespected by the students.
I remember listening one night to a report of a loud party in the Kendall Square neighborhood near MIT. A single cop arrived. He was white. The partygoers, about a dozen of them, were black. It's sensible in 1 on 12 situations -- even for something as relatively minor as a quality of life complaint -- for the cop to call for back-up. The cop did. At some point before the back-up arrived, a scuffle began. Who touched whom was unclear, at least to someone listening over the police radio. Within 5 minutes, more than a dozen Cambridge officers were at the scene -- most of the entire city's night shift deployment. 12 on 12. The cops are thinking that one of their guys is in trouble, and the partygoers are thinking that the cops have shown up because they are black. More scuffling. People are arrested. Lawsuits are filed."