I have found this most wonderful (if fairly lengthy) article, and thought you would enjoy having it brought to your attention.
It is so good, I think we should include it among the references in the "Politics is the Mind Killer" wiki page. But, before that, I submit it to you, and ask you: is there anything in this article that would warrant its exclusion from this site? I mean, besides the fact that it is about politics, and written by a notorious Social-democrat (And is that in itself grounds for exclusion?).
A rationalist has a hard time not reviewing history from that period and concluding that for all intents and purposes McCarthy was right about the extent of communist infiltration and may have indeed grossly underestimated and misunderstood the nature of intellectual sympathies for communism and how deeply rooted those sources of sympathy where in American elite intellectual tradition.
He basically thought he needed to eliminate some foreign sources of corruption and that he would be helped rather than sabotaged by well meaning Americans in positions of great power at least after they where made aware of the extent of the problem. He was wrong. For his quest to have been less quixotic he would have needed to basically remake the entire country (and at that point in time, the peak of American power that basically meant by extension the remaking of the entire West).
My impression of the situation (which has not been extensively researched) is that, although there really were plenty of spies and such, McCarthy's methods were largely ineffective at identifying them. Is my impression accurate?