The Assassination of Richard Nixon (2004) on Netflix

Fact-based story about a disturbed office furniture salesman who in 1972 concocted a plot to kill then-President Nixon by hi-jacking a plane to fly over the White House to drop a gas bomb. At the start of the movie, the man is separated from his wife and stressed in his job where he is made the butt of jokes and is an under-performer. Attempts to get his brother's old tire business resurrected with a black partner is rejected by the banks. When he is officially served with divorce papers, everything comes apart and Richard Nixon's broken promises comes to represent all the evils that have come down on him. A news story about a pilot that landed a helicopter on the White House lawn gives him the idea for his attack. Bolting onto a Baltimore plane, he attempts the hi-jacking.