Over the course of a long and successful legal career, Morris Ernst established himself as one of Americas foremost civil libertarians. Yet his advocacy of free speech – an advocacy that established the case law on which much of the subsequent jurisprudence is based – stands in stark contrast with his opposition to communism and his longstanding support for J. Edgar Hoover and his anticommunist campaigns. In The Rise and Fall of Morris Ernst, Free Speech Renegade (U Chicago Press, 2021), Samantha Barbas explores these contradictions to better understand Ernest and his legacy for our times. The son of Jewish immigrants, as a young man in college Ernst developed a gift for argumentation and an interest in progressive politics. Entering private practice after earning his law degree, he developed a reputation as a free speech crusader during the 1920s thanks to a series of high-profile legal victories and his leadership within the American Civil Liberties Union (ACLU). Yet even while developing a national reputation as a liberal attorney Ernst adopted a strident opposition to communism that sometimes put him at odds with his peers. Such was his antipathy to it that he emerged as one of Hoover’s most visible defenders on the left in the 1940s and 1950s, even supplying the FBI director with insider information on ACLU activities. As Barbas explains, such activities reflected his desire to remain relevant at a time when his greatest achievements increasingly lay behind him.