It does have a tone of "hatred will bring us together" at times. Perhaps the main thrust was to point the finger at well meaning liberals who in actuality probably are racist. The film is very self reflexive and that's why I think so many people were able to connect to it. By showing a wide variety of people this forces us in many ways to see how we would put ourselves in that situation, and almost daring us to act differently. The main point is that nearly all of these characters wind up doing the right thing when given the chance.