In November 1934 Major General Smedley Butler made headlines by alleging that he had been in contact with businessmen since July 1, 1933 who wanted him to lead a coup attempt against FDR. The allegations became known as the Business Plot. Congressional hearings concluded that there might be some substance behind the allegations, but that they could not be confirmed.
Contemporary press accounts indicate a wide spread belief that Butler fabricated the whole thing. Butler was passed over as Commandant of the Marine Corp in 1931 because he publicly accused Mussolini, falsely, in a speech of having run over a child. He never got over it and he ran unsuccessfully for the Senate in 1932 as a Republican. He then turned hard left, attacking capitalism and the military as being gangsters for the capitalists. That is what makes his entire idea of a fascist plot against FDR so laughable. By 1934 he was known as an ardent supporter of FDR and yet shadowy plutocrats wanted him to command a coup against Roosevelt? FDR obviously thought it was rubbish as there were no criminal prosecutions by the Feds of anyone named by Butler. Butler was a very brave man as attested by his two Medals of Honor. He was also a fabulist, to put it politely, of the first order.