“Schools are the major socializing agent of the country,” Art Spiegelman said pointedly one recent evening across the river from Washington — which is why he’s so concerned about how they’ve become battlegrounds over books.

The author of “Maus,” the first graphic novel ever to win the Pulitzer Prize, had just spoken to high school students, then at a community event at a middle school hosted by the Arlington Public Library in Virginia, all ahead of Banned Books Week.