Your theory makes a lot of sense!
Google “The Manchurian Candidate”...the OLD one with Frank Sinatra and Angela Lansbury,(Not the new one with Denzel Washington)
It takes place after the Korean War, and a released POW had been psychologically tortured to assassinate a legitimate Presidential Candidate so that a Communist Plant would be elected instead.
It is a deep and scary movie, and not at all far-fetched.
(LOL!!!)