“Oddly Normal,” John Schwartz’s memorable book about his young son, Joe, discovering he was gay, overflows with lessons for parents of all kinds of children. Consider, for instance, the attempt by Schwartz and his wife, Jeanne Mixon, to move Joe out of the classroom of an abusive teacher.

Schwartz, a New York Times reporter who used to work for The Washington Post, tells a story that will ring true for many Washington area parents, even though it happened in an affluent New Jersey suburb of New York City. It shines a bright light on a major reason why so many of us feel the people teaching our children don’t always have our best interests at heart.

Mr. Fourth, as Schwartz calls the teacher he came to distrust, sounded at first like a good fit for his bright but sometimes difficult son. The teacher was known for encouraging humor, discipline and wide-ranging discussions. Schwartz discovered too late that the man was also struggling with cancer and had the habit of regularly harassing two students each year, usually boys who were somehow different.

So the class’s only Hispanic child and Schwartz’s son Joe became Mr. Fourth’s victims that year. The teacher was “disorganized, domineering, and volatile,” Schwartz wrote. “When frustrated, he was quick to yell at kids.”

The Hispanic boy suffered in silence, but Joe Schwartz had a quick mind and a sharp tongue. When Mr. Fourth tried to teach his students “patriotism and the evils of Islamic fundamentalism,” Schwartz wrote, 9-year-old Joe challenged him. “There are white terrorists,” the boy said.

“Name one group!” the teacher said loudly.

“What about the Michigan Militia?” said Joe, who read widely.

Joe’s erudition earned him no respite. The bullying pushed back into an angry shell a child who had made progress dealing with teachers and other students. A crossing guard who used to get friendly greetings from Joe reported to Mixon that the boy now rushed by with his head down. “What is that teacher doing?” the guard said.

Schwartz and Mixon were sympathetic to the teacher’s health problems. They didn’t want to confront him. They just wanted him out of their son’s life. They asked the principal to move Joe to another class. “I argued that he wouldn’t be subjected to a daily power struggle, and the obviously ill teacher would get a break as well,” Schwartz wrote.

The principal “sighed and told me it was against the school’s policy to transfer kids from one teacher to another: ‘We almost never do that.’ All of his teachers, he calmly explained, were ‘certified and qualified,’ ” Schwartz wrote.

Many of the parental frustration stories I hear emerge from principals’ entirely understandable tendency to take their teachers’ side in any dispute, unless the instructor is already on the principal’s bad list. The principal has to deal with the teacher many times a week, perhaps for many years. Parents are rarely seen and soon move on to the next school with their children. Allowing the transfer of a child from one classroom to another suggests disloyalty to the principal’s staff, and doubts about a teacher’s competence.

Yet it seems an obvious solution to a situation like Schwartz’s. I asked Washington area school districts whether they also discouraged such moves. Officials in Stafford, Calvert, Carroll, Prince William, Arlington, and Fairfax counties said they left it to the principal. What does that mean? If you are a principal, tell me how you handle such requests by contacting me at mathewsj@washpost.com or washingtonpost.com/class-struggle.

Frederick County has a different approach. It appeals to parents who think schools should experiment with unorthodox ideas before rejecting them. They allow schools to move a student “on a probationary basis.”

I suspect Joe Schwartz’s parents would have gone for that deal, and both teacher and child would have been the better for it.