****At the time the issue was whether the CP was simply an fifth column of the USSR at the height of the cold war, and implicitly whether the New Deal was tainted by being run by Commies. (That was the big deal with Hiss even more than the Rs.)
jks ****
There was that -- but as usual in the u.s. there was a racist element (as there is, incidentally, in many of the "left" conspiracy theories re 9/11): Those dumb russian peasants were too stupid, too backward, to ever make a bomb by themselves. (Those dumb arabs are two stupid, too backward, to pull off as sophisticated an action as 9/11 -- it must be the CIA.) Anti-semitism of course was also involved.
The same sort of thing was behind the universal horror that swept America when the Soviets put Sputnik into space. One night when I left my office in Haven Hall at U.of M. I found a huge cluster of undergraduates outside the door: they wanted to get into Mason Hall to see the A.P. ticker tape that ran there. They just couldn't believe that the Russians had actually done something _before_ the Americans had. :-) The same disbelief accompanied the Soviet making of a nucler bomb -- there had to be some other explanation. What better than that a couple of those tricky Jews had stolen "The Secret."
Eisenhower, if I remember correctly, officially offered in public to commute the death sentences if the Rosenbergs would fess up and incriminate the rest of those commies. That's torture by any civilized standard.
Carrol