As a philosophical liberal, i am completely comfortable with the existence of affinity groups in middle schools and hight schools. Where really start to worry is when this is facilitated id in a way that becomes, in effect, mandatory. If te school, with its athoritative voice, tells 16 year olds or 12 year olds, or sometimes seven year old, the most important thing about you is the colour of your skin, that to me, seems really worrying and counterproductive.