AMERICAN HISTORY IS STAINED by recurring periods when our founding ideals — of an open society that upholds the free marketplace of ideas and diverse political viewpoints — have been sacrificed to fear and hysteria: reactions to threats, foreign and domestic, real and imagined. During these dark chapters, cherished democratic institutions such as the Supreme Court, Congress, and state legislatures, as well as the press and civic organizations, instead of standing up for the rights and liberties enshrined in the Constitution, often proved weak and spineless, encouraging and at times even leading many of the worst violations.

One of these tragic periods reached its heights during the 1940s and 1950s, popularly known as McCarthyism, when fear of communism prompted excessive public and private efforts to  punish unorthodox ideas and advocacy. In Priests of Our Democracy: The Supreme Court, Academic Freedom, and the Anti-Communist Purge, Marjorie Heins juxtaposes her compelling and distressing account of the anticommunist purges that reached into the ivory towers of our colleges and universities with a chilling cautionary tale that asks whether history is repeating itself through the repressive reactions to 9/11. Have the earlier witch hunts that targeted alleged communists (with a disturbing and disproportionate focus on Jews) been replaced with an obsessive targeting of alleged terrorists (with a disturbing and disproportionate focus on Muslims)? Have we learned anything from the excesses of McCarthyism, or are we condemned to repeat them?

Heins, the founding director of the Free Expression Policy Project, engagingly addresses these and other urgent questions by deftly telling the stories of professors and teachers victimized by academic purges, while she deftly navigates more than 50 years of legal battles and constitutional controversies.

In 1951, George Kennan, a keen observer of the Cold War, warned — in words as relevant today as then — that the blinding fear of communism posed a danger that Americans would become

rather like the representatives of that very power we are trying to combat: intolerant, secretive, suspicious, cruel, and terrified of internal dissension because we have lost our own belief in ourselves and in the power of our ideals.

Heins places her account within the context of anticommunist hysteria at the national level, including President Harry Truman’s 1947 executive order that created a program of sweeping loyalty investigations (of employees in every federal agency), the attorney general’s list of “subversive organizations,” and, at the state level, the infamous Rapp-Coudert investigations in New York, in which more than 500 professors, teachers, staff members, and students were interrogated, over 80 of whom were fired, resigned, or did not have their contracts renewed.

The heart of the book is Hein’s comprehensive and accessible analysis of the fate of academic freedom from the Supreme Court’s 1952 decision in Adler v. Board of Education to its 1967 decision in Keyishian v. Board of Regents. Both cases dealt with New York’s Feinberg Law, which created a complex system of procedures to investigat...