On July 1, 1933, Butler met with MacGuire and Doyle for the first time. FDR was already president when the JP Morgan inspired Business plot coup was being planned.
They wanted MacArthur because he would have easily gone along with a fascist model and a coup. But he was radioactive with veterans after he attacked the bonus marchers with cavalry using flats of swords, tanks, and vomit gas.
So they went to Butler who they thought might play ball.
Instead, he exposed them. And remember, at that time Mussolini and his fascism was considered the modern marvel and more than a few admired that approach.
My Italian MIL tells of childhood friends who went back to Italy because Mussolini was getting the trains to run on time. Some of her peers did not come back as they were of draft age in Italy.
That must have sucked.