Racism exists simply because of culture differences, and as mortal human beings, people tend to either fear or despise any change that contradicts with their own perceptions of cultural norms. It probably began early in human history when people of different regions of the world made first contact, where people would encounter people of other races and think they're odd because all they really know is of what they see in their own regions. And like Sean said, racism isn't something that can just disappear by the snap of a finger because it has (unfortunately) been a part of humanity since the Middle Ages and maybe even before that. Humans are creatures of habit. Humans generally dislike change. Humans prefer consistency and sometimes react unfavorably to anything that proves otherwise. Even so, I think racism is a pretty broad term. It does mean discrimination against another race, but its origins may not have been so intentionally brutal. It's just that us humans are quite shallow and have evolved racism into a negative mindset of action. Which would be to believe that one's race is superior to another, or to express hatred. No one's really sure why or how this came to be, but all we can do for ourselves is to be nice to other people. It's common sense. Don't discriminate other people in general. Whether it be because of race or because of political views, it's never okay to hate on someone if they never did anything wrong to you.
