The fundamental aim isn't to thrust low performing kids into high performing classes and schools. It's to keep the high performing kids from self-sorting and se

The fundamental aim isn't to thrust low performing kids into high performing classes and schools. It's to keep the high performing kids from self-sorting and segregating themselves from the other kids on the theory that 1) high performing kids will model better habits for lower performing kids and 2) minimize concentration of at-risk kids. #1 is fundamentally misguided, for reasons I explain elsethread. There's alot of truth to #2, but these movements are occurring in school districts where social policy has done about all it can to prevent concentration of at-risk kids, and short of marching high performing kids (poor and rich) at gun point into underperforming schools, there's not much more that can realistically be done. Families can and will send their kids to private school, even poor families. Parochial schools in these cities are brimming with students, including students from poor families.