On a Monday night, just after six, Alicia Williams waits for the last stragglers to take their seats in her cramped classroom at the Washington corrections center. Her students braved western Washington’s fall weather to get here and they enter the room still ruffled from the wind, their khaki uniforms flecked with rain. There is no rush. Instead of the lesson she planned to teach, Williams will be relying on hastily adjusted notes and on-the-spot explanations. She’d just heard she wasn’t allowed to teach the book her class was scheduled to discuss that night. The course is English 233, children’s...