In 1933, someone associated with the Du Pont interests tried to hire Butler to organize a coup to overthrow Roosevelt. It's never been clear how serious a plot this was, but Butler didn't go along and the plot died.[1]
Supposedly, Prescott Bush was one of the people behind it.
There was a lot of fascination with Fascism and dictators around this time, a now creepy movie from this time is "Gabriel Over the Whitehouse", which promotes the idea of a Roosevelt-like president becoming dictator: https://www.youtube.com/watch?v=ivMiVQjGeyg
There's also "It Can't Happen Here" by Sinclair Lewis, from 1935. It envisions a totalitarian dictatorship taking over the US.