I'm aware of that, but the CP wasn't _merely_ carrying out orders from Moscow. I don't think Moscow ordered the CP in Wisconsin to support McCarthy in the Republican primary because he would be the easiest Republican to defeat in the general election. The CP was large there, and its voters in the Republican primary made the difference.
And of course the U.S. did not in the least "support the antifascis cause abroad." Instead it joined France & England in refusing to sell arms to the Spanish Republic, thereby dooming it to defeat.
I have a good deal of sympathy and even admiration for the rank and file of the CP through the '60s, & Truman & Eisenhower's repression of the Party is a living shame. But one can't excuse tits gross tailing of the DP merely on orders from Moxcow.
Carrol