“The Venona Secrets, Exposing Soviet Espionage and America’s Traitors. By Herbert Romerstein and Eric Breindel.
Follow that up with: Blacklisted by History: The Untold Story of Senator Joeseph McCarthy, by M. Stanton Evans.
It's dry reading but I'm making my way through it.
"McCarthyism", properly speaking would refer to a concerted effort in the direction of unmasking real traitors, spies, and enemy propagandists in positions of political or military power, or of social influence.
We need some "McCarthyism" right now, to unmask the socialists, fascists, and islamists currently infesting government and media.