With all due respect, I think it is you who need to read up. The release of the transcripts of the decrypted "Venona Papers" should have removed any lingering doubt in any reasonable person's mind that Joe McCarthy was EXACTLY correct is saying the US Government had been infiltrated by communists and Soviet agents up to the highest levels of the government. You might start with "Venona: Decoding Soviet Espionage in America" which, although showing there was no proof of the treachery of certain persons on McCarthy's various "lists", supports his basic assertion of communist infiltration of the US government.
And, of course, it must be borne in mind that the Venona messages that have been decrypted represent a small fraction of Soviet cable traffic and it is mainly through the mistake of certain Soviet cryptographers in reusing pages of one-time pads that any cables could be decrypted at all.
Once you finish that one, you might also take a glance at "In Denial: Historians, Communism, and Espionage" (by the same authors) that speaks to the liberal revisionist history that you, apparently, have swallowed regarding Senator McCarthy.
What a croc. He may very well have had a few commie names. But he smeared a lot of people for nothing more than being in the entertainment business. That is a fact. He was a despicable little man. The people trying to lynch Cain are no less despicable.