American culture's tolerance for Communists and “fellow-traveling” sympathizers fluctuated according to both domestic and international circumstances. Communism was broadly acceptable during the early 30s when federally run projects such as the WPA were benefitting many and when the Great Depression vividly posed the question (and nodded toward the negative) of whether capitalism was viable. It was also possible to be a Communist during the last half of the 1930s (when most logical empiricists arrived in America) because Moscow and the CP reached out to progressive and liberal organizations to form a united, “popular front” against Nazism and fascism. During the last years of the war, America and the Soviet Union were official allies and thus not communism but criticism of communism could be deemed unpatriotic.
Always in the background, however, and filling the gaps between these interludes were events and circumstances that eroded communism's popularity and acceptability among intellectuals and the broader public. Beginning with Stalin's rise to power in the late 1920s, increasing numbers loss respect either for the Communist Party or for the idea of Communism. For the many intellectuals who were devotees of Leon Trotsky, Stalin's persecution of Trotsky and other enemies and rivals was dismaying enough, even without the insulting show-trials through which Moscow asked the West to pretend that Stalin's consolidation of power was altruistic and justifiable. Equally damaging was the debacle of Soviet agrarian reforms in the early 30s (known as “five year plans”) that led to widespread starvation and death among Soviet peasants.