The Obama administration is aware of these developments, though you might question how it has chosen to respond to critics. “It’s fascinating to me,” said Mr. Duncan in 2013, “that some of the pushback is coming from, sort of, white suburban moms who—all of a sudden—their child isn’t as brilliant as they thought they were and their school isn’t quite as good as they thought.”

More recently, the administration has pivoted from insulting parents to threatening them. Mr. Duncan told an education conference in April that if the boycott numbers continue to rise, “then we have an obligation to step in.”

His spokesman later informed reporters that the administration is considering whether to withhold federal funding for districts with test-participation rates below 95%. Given that there is no political will or effective mechanism for punishing test opponents without turning them into martyrs, this is an idle threat. The districts doing most of the boycotting are affluent and not dependent on federal money, which in any case parents could easily replace out of pocket.