In the spring of 1947 the House Committee on Un-American Activities (better known as the House Un-American Activities Committee, or HUAC) began conducting a well-publicized investigation of Communists in the motion picture industry. By the fall, they were ready to hold public hearings. The American public paid close attention as a string of well-known stars, producers, writers, and directors were called to Washington, D.C., and grilled.

Pauling knew many of them through his work with ICCASP. At least one of them he considered a friend: Dalton Trumbo, "one of the most gifted writers in Hollywood," as Pauling described him. Trumbo refused to cooperate with HUAC’s investigation. Instead of answering questions, he submitted a written statement in which he described an atmosphere "acrid with fear and suppression" created by HUAC and other investigatory committees. Washington, D.C., he wrote, had become "a city in which old friends hesitate to recognize each other in public places; a city in which men and women who dissent even slightly from the orthodoxy you seek to impose, speak with confidence only in moving cars and the open air." When Trumbo tried to read his statement aloud, he was gaveled down. After the hearings, he and nine other non-cooperators were singled out for further legal action. They would become known as the Hollywood Ten.