“As inequality has grown, as its negative consequences have become harder and harder to ignore, our response has been to put more and more weight on the educational system, to look to school reform as the means of closing the 'achievement gap' and of guaranteeing the increasingly illusory promise of equal opportunity. We ask the education system to expiate the sins of the rest of the society and then condemn it as hopelessly broken when it doesn't prove up to the task.”