There are a lot of reasons why racism still exist today. To try and fit in a comment on a forums would be impossible.
Although there are many reasons, these are the main ones (in my opinion.) The media, they report what's interesting and makes movies about it. How many movies have you've seen where the black person was doing drugs, robbing a bank, ect; compared to how many white people do that same thing in movies. It's an unbalanced ratio to say the least. Because of this, people rationalize who they are, and what they are meant to do in the world. A black person needs to play in the NBA. An Asian person needs to be a genius. A white person can't be a dancer because they don't have rhythm? I could go into further detail with so many more races, but it'd be a waste of time. Another reason is people hold on to the past. They want to remember the good times they had, as a child growing up drinking lemonade while sitting on there front porch. If they remember that, what's stopping them from remembering all the other things from their childhood, where there parents told them not to hang out with the black kid across the street. The Asian kid in his AP Geometry class. There is nothing. Kids just have to be smart enough to learn to be their own person.
Racism will always be in the world, no matter how much a person tries, there is always going to people out of the 7 billion others.