I shouldn't have been surprised that a lot of people took Obama's remarks about Gatesgate as a slur on the Cambridge cops in general and -- naturally -- on white people in general; people are, after all, hypersensitive about being called racists. That Obama was obviously right is neither here nor there.
Much of the outrage (Althouse, e.g.) supposedly has to do with Obama's admitting that "he didn't know all the facts of the case" and -- allegedly therefore -- that he had no right to say anything about it. This is illogical. Given a number x that's less than six, I know that x is less than ten regardless of what x actually is. Similarly, in Gatesgate, one can reasonably assume that the police report puts things in about as pro-cop a light as possible. Well, the police report doesn't offer a remotely valid justification for the cop's telling Gates to step outside so that he could arrest him for being "tumultuous." (If Gates had a sense of humor about this, he might appreciate the wonderfully Yeatsian adjective.) Therefore, one can sensibly assume that, whatever turns out to have happened, it isn't going to justify what the cop did.
It's hard to escape the sense that a certain white demographic (even in Boston!) is very fond of playing the victim.