On a recent morning, Ramón González, the principal of M.S. 223, a public middle school in the South Bronx, arrived at work as usual at 7:30, stripped off his coat and suit jacket, deposited his tea and toast from a nearby diner on the cluttered conference table in his office and hustled down the hallway to the school’s back door to greet arriving students. González had a busy agenda for the day. Among other things, he needed to get to work on a proposal for the city’s Department of Education to expand 223 into a high school.

At 10, González was finally about to sit down at his computer, when he was interrupted. A young teacher came into his office in tears, unable to figure out what was going on with an eighth grader who had just transferred to 223 from a public school in Florida, was way behind in class and had been wandering around the school’s hallways between periods, looking lost. González knew almost nothing about the girl. Like many of his students, she turned up at 223 with no more than a utility bill to prove she lived in the neighborhood. He calmed the teacher and started trying to figure out what was happening. (When he finally reached an administrator at the girl’s old school days later, he discovered that she had been classified with a severe learning disability.)

Next, González was informed that the three free books that each of his school’s students was entitled to — under a nonprofit program to promote literacy in poor communities — had never arrived. He needed to chase them down. (As it turned out, they wound up at the wrong school.) As he was doing so, he learned that a former teacher who had physically threatened him, members of his faculty and even some students, and whom González had spent years trying to remove from the classroom, was challenging his termination.

There was also the matter of the eye tests. For five straight days, González had been trying to get through to someone at an organization that does free ...