Racism is about power. It's about realizing that each of us in powerless in this great big world, and so we band together, and find some way to grab a little power for ourselves. Strength in numbers.
It's easier to find power if you've got people who are even more powerless than you are. That's where the racism comes in. That's where the bigotry and hate comes in, because at some level, we understand that, but for the grace of God, that could be me. And that terrifies us.
So rather than fight the power -- which would entail actually putting some skin (no pun intended) in the game and putting our necks on the chopping block -- rather than pick up a pitchfork or a torch and go storming the castle and grabbing power where it actually lies, we're content to snipe power where we can find it, even if it means hurting innocent people.