I've been reading Hilton Kramer's Twilight of the Intellectuals, about the liberal intellectual set during the Cold War. While he starts with a discussion of the Hiss case, he rapidly moves on to the more general problem of Stalinism, and the difficulty the left had in confronting it. There were two blacklists, one by people who didn't like Communists, and one by Communists, who didn't like liberals pointing out they were communists. The whole history of Stalinism among the left, and those who were willing defenders and obfuscators of it, is a seamy and revolting one, the white-washing of which has allowed the Left, by and large, to escape the intellectual cleansing it needs.