Anthony Romero had led the American Civil Liberties Union for only four days when the attacks of September 11, 2001 presented civil libertarians with their greatest challenge in decades. Since then, Romero and the ACLU have waged a continuous struggle in the nation's courts to ensure that the Constitution does not become a casualty of the war on terror. A son of Puerto Rican parents, and the first member of his family to graduate from high school, Romero earned law and public policy degrees at Stanford and Princeton. He is the sixth director to lead the ACLU since it was first founded, to...