Voucher or Affirmation?

Terry Moe of Stanford University writes in NYTimes in favor of public school voucher system. He reported, "... Washington's public schools got some very good news when Congress approved a plan to provide school vouchers to low-income families in the nation's capita...". Milton Friedman, Gary Becker, and the likes, sure are happy to hear about this. Vouchers are meant for students from low income families that could be spent at private schools (or public schools -- but in general, elementary private schools are in better shape, you do the math). Friedman proposed this policy long time ago. He believed that poorer students attended the worst public schools, since they could not afford either private schools or good suburban schools. Vouchers help level the playing field. Agreed.