BARBARA FORREST knew the odds were stacked against her. “They had 50 or 60 people in the room,” she says. Her opponents included lobbyists, church leaders and a crowd of home-schooled children. “They were wearing stickers, clapping, cheering and standing in the aisles.” Those on Forrest’s side numbered less than a dozen, including two professors from Louisiana State University, representatives from the Louisiana Association of Educators and campaigners for the continued separation of church and state.

That was on 21 May, when Forrest testified in the Louisiana state legislature on the dangers hidden in the state’s proposed Science Education Act. …