Racism's trajectory is such that it is quickly disappearing. That is the case even in the deep south where I'm from (this is fairly profound considering our civil war defeat is still a big deal in the minds of many), but rather the racism you do encounter is in response to perceived injustices such as those I listed. Thus the hyper-vigilance perpetuated by the media does more to harm racism's disappearance than to hasten it's natural death.

Edit: Also, because racism is illogical. Irrational ideas tend to be replaced by good ones in the "free market" of ideas. There is no reason to beat tolerance into people, simply show show them the compassion and unity that equality leads to, and contrast that with the ridiculous KKK guys in goofy white cone hats and piss-stained bed sheets and let them make up their own mind.