There's a Wikipedia entry called "Business Plot". NPR also has an entry entitled "When The Bankers Plotted To Overthrow FDR". Rolling Stone magazine has one called "The Plot Against American Democracy That Isn't Taught in Schools".

Look it up.

A group of wealthy businessmen plotted to install a retired general, Major Gen. Smedley Butler (Gen. Gil Dillenbeck in the film), in the WhiteHouse (without any election). As a dictator. That was their answer to the presidency of Franklin Delano Roosevelt.

Not a wild conspiracy theory, but an actual historic conspiracy. The genuine article.

Why else would half the people writing reviews find fault with this movie? Except perhaps to drive down its rating, eh.