People attack what's different. Racism is just a classification that falls under the general heading of douchebaggery. White people aren't any nicer to each other. The only real exceptions are specific hate groups and "master race" types. "Casual" racists are assholes to everyone. They'll provoke you where you're most sensitive. They know minorities are sensitive to racism just like an overweight person is sensitive to being called "fat." They're just as likely to call the police on someone who looks like a druggie or wears baggy clothing if it doesn't fit with their idea of their neighborhood should be. They also get worked up about the homeless. They get worked up if there are two men of any race walking in the same direction behind them on a dark street. Fear mongering makes us distrust anything that is different, but the fear of racism also makes it difficult to establish the true motives of the accused. If we paint everything as racism, it dilutes the efforts against it and jades the next generation in the topic altogether.