One thing to keep in mind about America is the idea that we're some big melting pot is only true for large metropolitan areas. When you get into the "heartland" and rural or agricultural areas, the segregation becomes very palpable. Even in some of the outlying areas of large cities, "ghettos", you're going to find a community comprised mostly of one race or the other. Truth is many Americans will go their whole lives never meeting anyone from another race during their own personal life. Most people's exposure will be through their work, school, etc. In fact there's some areas where the racial diversity is so low, that the only time they may see a person of color is on a TV.
I mean, if you think about states in the "mid-west" and the "heartland" where communities are nearly 100% Caucasian, what is their experience with black people or minorities going to be? More than likely, a jailer in one of these communities has put more black people in jail than he's ever actually spoken to. It's not hard to see how the context of that situation would severely effect both parties perception of the other.
When you consider that most of America isn't one of those big metropolitan melting pots, it really becomes apparently how and why such a large portion of people can view other races with ignorance. Black people arguably have it worse than any other ( except perhaps muslims right now ) because the media is literally inundated with images and depictions of blacks being criminal in nature. I'm not saying "There's no positive black role models for black youth to look up to," what I am saying is the media has given us this false impression that the majority of black youths are troubled kids lacking guidance and blah blah blah. You know it's the kid that is playing around in the projects with a replica pellet gun that gets shot and all the attention of these viewers, but when it's sweeps week and time to go find some feel good story about a kid's high school science project, do they ever show the black kid's? Hell the only time they showed the muslim kid's was when some racist asshole thought it was a bomb!
Where I grew up there's hardly any black people, we're mostly 50%/50% Hispanic in white. One of my first childhood friends was black, but ironically his dad wasn't okay with him hanging out with a white kid. You'd be surprised with how much Hispanics hold the same ignorant and racist views on blacks as whites do. It makes it pretty clear that there's a type of manipulation at play, whether intentional or incidental. I believe it's more incidental, the media just wants ratings and viewers and they don't care what effects it has on society to get it. Sex, drugs, violence an scandal are what sells, so it really shouldn't be any surprise that Americans growing up today saw 100 images of blacks being arrested and treated like criminals on COPS and Judge Judy to every 1 image of blacks reading children's books on "Reading Rainbow" or saving the butts of a whole crew on "Star Trek". Even when the media doesn't portray blacks in a negative way, it's still often stereotypical. This is a lot less prevalent in media these days, but think back about twenty years, to where people were talking about how ground-breaking the Cosby show was, this sweater-wearing, no jj-joined-a-gang having black family sitcom was probably the first introduction most American homes had of a "normal" black family.
So considering the age of most of the people who effect these issues... Judges, DAs, prosecutors, and the police.... Do you think any of these people are young enough to have been raised in our more enlightened media presence? I mean people don't consider the fact that these people are so old that they very likely grew up calling black people "negroes". All this racial misconception and ignorance has had 20-30 years of gestation. This idea of a new dawn of racial enlightenment in America is total horsesh*t when most of the people that are "the powers to be" grew up watching Archie Bunker and think just like him. Their only link to black culture is The Jeffersons or Good Times.