Keeper of the Flame is "truly provocative in that it was one of Hollywood's few forays into imagining the possibility of homegrown American Fascism and the crucial damage which can be done to individual rights when inhumane and tyrannical ideas sweep a society through a charismatic leader.".....
[Forest] had been corrupted by the adulation he received and plotted to use his enormous influence to turn Americans to fascist ideals and gain control of the United States. She shows O'Malley papers stored in the arsenal which reveal how Forrest (backed by secretive, ultra-wealthy, power-hungry individuals) planned to use racism, anti-union feeling, and antisemitism to divide the country, turning social groups against another in order to create the chaos that would let him seize power. .... WikipediaWOW! Remind you of anyone?
I'm watching the movie and researching it at the same time. It matches my recent theme in blogging about right wing populist movements. Filmed in 1943 it was clearly an anti-fascist movie. Spencer Tracy finds out that a popular - populist - leader dies in an accident - he discovers some negative info indicating fascist tendencies.
Robert Forrest's organization was called "Forward America" and Spencer Tracy begins to smell a rat. There are self-organized chapters all over the nation, with a big youth movement -- modeled it seems on Hitler youth.
More from Wikipedia:
Keeper of the Flame (film)
Keeper of the Flame Directed by George Cukor Produced by Victor Saville Screenplay by Donald Ogden Stewart Based on Keeper of the Flame
by I. A. R. Wylie
Starring Spencer Tracy
Music by Bronisław Kaper Cinematography William H. Daniels Edited by James E. Newcom Distributed by Metro-Goldwyn-Mayer Release date 
- January 28, 1943
Running time 100 minutes Country United States Language English Budget $1,172,000 Box office $3,222,000Keeper of the Flame is a 1943 Metro-Goldwyn-Mayer (MGM) drama film directed by George Cukor, and starring Spencer Tracy and Katharine Hepburn.The screenplay by Donald Ogden Stewart is adapted from the novel Keeper of the Flameby I. A. R. Wylie. Hepburn plays the widow of a famous civic leader who has suddenly died in an accident, while Tracy portrays a former war correspondent who intends to write a flattering biography of the dead man, only to find that his death is shrouded in mystery. Screenwriter Stewart considered the script to be the finest moment of his entire career, feeling vindicated by the assignment as he believed that Hollywood had punished him for years for his political views. Principal filming began in the last week of August 1942, four months after the release of the novel, published by Random House. The entire picture was filmed on a sound stage, with no location shooting. Hepburn had already begun her extramarital affair with Tracy, and due to his heavy drinking, she became his constant guardian during filming.The film was screened for the Office of War Information's Bureau of Motion Pictures on December 2, 1942, where it was disapproved of by the Bureau's chief, Lowell Mellett. Keeper of the Flame premiered to a poor reception at Radio City Music Hall on Thursday, March 18, 1943. MGM head Louis B. Mayer stormed out of the cinema, enraged by his having encouraged the making of a film which equated wealth with fascism. Republicanmembers of Congress complained about the film's obviously leftist politics, and demanded that Will H. Hays, President of the Motion Picture Production Code, establish motion picture industry guidelines for propaganda. Cukor himself was highly dissatisfied by the film and considered it one of his poorest efforts. Nonetheless, today the film is seen more positively, with one critic concluding that Keeper of the Flame is "truly provocative in that it was one of Hollywood's few forays into imagining the possibility of homegrown American Fascism and the crucial damage which can be done to individual rights when inhumane and tyrannical ideas sweep a society through a charismatic leader."