Fair enough. I do not always remember which user names are which so I apologize.
In any case, I am not convinced communism is the biggest threat the U.S. has faced.
We have over 100 years now of progressive success after progressive success. Progressives are clearly a much bigger threat than the communists are. Right?
Politically, no. Socially, absolutely. Gramsci's redirection of communism to that effect is what came to the US via the Institute for Social Research.
As to the Progressives, it was one of them who rescued the IFSR to plant them at Columbia as but a part of a much larger and more destructive plan, in the person who shall remain unidentified in this discussion pending release of my next book.
How specific is your definition of a “progressive” and “progressivism”? A predisposition to some promising novelty, whatever that may be? In this sense Marxists consider themselves progressive for ushering in a communist utopia. Social liberals, too, would think themselves to be progressive. They quibble about doing it fast or slow, but they are all progressive. So the term can be vague.
If more specific, it’s the moniker of the industrialists defining the Progressive Era. Like the communists, they fix social ills with the promise of technology and government.