With how diverse the population has gotten, there will always be a minority groups in a school. This group could be any race, which includes white, black, Asian, or hispanic. In addition, it includes physical traits and the cliques people stick to. In any environment, especially one with so many immature minds, one who are different are more likely to get picked on. Not only because they are different from the rest, but also because they are less likely to have people to back them up.
In any case, not all environments are the same. While physical bullying still takes place, it has become less common place. There are good Samaritans who may stop cases of overt physical bullying when they see it.