I wonder what was widely known about the gulags and pogroms during the lifetime of Stalin. Until Aleksandr Solzhenitsyn's One Day in the Life of Ivan Denisovich was published in 1962, the atrocities of the Stalin Regime were not known in detail, and much of the condemnation of Stalin and the Soviets sounded a whole lot like anti-Communist propaganda.

If the loudest voice condemning Joe Stalin was Joe McCarthy, wouldn't you take all such condemnations with a grain of salt?

And there were no voices within the Soviet Union to condemn Stalin - they were all suppressed.

-Joe-