The Business Plot was an alleged 1933 conspiracy, which, according to former Marine Corps Major General Smedley Butler, involved wealthy businessmen who were plotting to create a fascist veterans' organization with Butler as its leader and stage a coup to overthrow President Franklin D. Roosevelt. The alleged coup was supposedly supported by a private army of 500,000. The New York Times newsroom gave the plot front-page coverage until an editorial characterized it as a "gigantic hoax". No one was prosecuted.
The allegations were investigated by a House Committee with the Jewish and paid Soviet NKVD agent Samuel Dickstein as vice-chairman. Communists would likely have had an interest in spreading smears regarding such an alleged capitalist-fascist conspiracy.
Smedley Butler had been forced out of the military and was almost court-martialed for publicly spreading rumors of Benito Mussolini killing a child with his speeding automobile. After this, Butler became a publicist for left-wing causes, voted for the socialist Norman Thomas, and at the very least was willing to lecture together with Communist Party USA speakers. In 1935, he wrote the book War Is a Racket, claiming various negative associations between capitalism and US foreign policy, which has been frequently cited by Communists and other leftists.
Leftist Wikipedia despite this describes this conspiracy theory as if it has been proven to be true in some form. Dickstein being a covert Communist agent is not mentioned in the article on the "Business Plot".
- Maverick Marine: General Smedley D. Butler and the Contradictions of American Military History (review) https://muse.jhu.edu/article/372062/summary
- Schmidt, Hans (1998). Maverick Marine: General Smedley D. Butler and the Contradictions of American Military History. University Press of Kentucky. ISBN 0-8131-0957-4.