What is the drive behind racism in America?

Seriously!!! I need someone to help me understand. Everywhere I go on the internet I see it. Everywhere I go in the community I see it. Even on Youtube. You tube is for watching and posting videos that an individual wants to watch. So why are there so many racists comments in rap artist's videos. There were several people who posted 20 or more comments and responses to comments. If you hate black people so much why are you commenting and posting so many comments on that video? Your making that person more and more famous. You do not have to watch that video. The same for white supremacist videos on youtube. That is their business. Why are you, as a black person, watching and repeatedly commenting on such nonsense. You are just fueling it. If black people didn't care that racist white people hated them and vice versa this country would be a much better place.