What is the theme in Scoundrel Time by Lillian Hellman?

The Roots of McCarthyism is the main theme of this book. Garry Wills, author of several books including "Nixon Agonistes" wrote the introduction to "Scoundrel Time" by Lillian Hellman. In his introduction, Wills explains that the environment of distrust was put in motion by President Harry S. Truman in 1947, several years before the House began their investigations of private citizens perceived to be un-American. After the House began its inquiries, Joseph McCarthy got on the bandwagon in the Senate and propelled further investigations and ultimately began bringing charges. He went after these targeted people, while gaining publicity for himself, in an aggressive, unrelenting manner.