How is busing students not racist?

First off, I would like to say that the concept genuinely confuses me. Here in the States, we supposedly want to live in a society that looks beyond race. I understand that back in the 60s such a thing was necessary, but it is 50 years later now and busing continues in many areas.

It just seems to me that busing kids across town to even out the racial demographics in the various schools is a textbook example of racism. I fail to see how basing where kids go to school on their race is okay; I don't understand how it's not racism.

It also seems to me that it would invite violence. When you have disparate groups of people from many different races and socioeconomic classes (though my main concern is the difference in the socioeconomic classes) being forced to coexist, it just seems to me like there would be an endless amount of clashes. Particularly in the high schools with hormonal young males who are naturally inclined to try to be an alpha.