“Isolationism was massive and needed NO help from the left, at all. It was so big, the British infiltrated our polling orgs to try and change opinion (Thomas Mahl, “Dangerous Deception”). They failed.
The left was real, tiny, and irrelevant.”
They had “an” effect. Again, Harry Dexter White as Assist. Sec of Treas was the most important. His impact was not negligible, but didn’t “give China to the Commies.”