No fight for civil liberties ever stays won, wrote Roger Baldwin (1884-1981) in 1971. He was in a position to know. After working hard to preserve the right of Americans to free expression during World War I, he founded the American Civil Liberties Union in 1920. The ACLU quickly became, and remains to this day, the staunchest defender of American civil liberties. Woody Klein has selected from Baldwin's vast writings those essays that are most pertinent...