The passage for the seventh-grade lesson was blatantly offensive — an excerpt from a 1938 anti-Semitic children's book. But that was the point: to provide students in the Santa Ana school district with a perfect illustration of insidious propaganda. In the book, a mother and her son gather mushrooms in the forest, and she explains that, as with mushrooms, there also are poisonous people. Slapping his chest in pride, the boy says, "Of course I know, mother! They are the Jews!" When teachers expressed misgivings about the material, which also included an excerpt from a speech by Hitler, officials struck...