Prejudice is a great timesaver. It enables you to form opinions without bothering to get the facts. Yup, Obama spoke with a preconceived notion that policemen are bigots.
I would think you would have to be a politically astute policemen to work in the People's Republic of Cambridge. I can tell you for a fact that a red-necked cop would not last a month in that communist infested city. (In my most humble opinion)

PS. Communist infested may be too strong a description but the city is world renowned for it's extreme liberal leanings.