To gain the feel of Richard Nixon, Sir Anthony Hopkins watched on tape almost every speech Nixon ever made several times. He also met some people who knew Nixon and could lend Hopkins some insight on him.
Writer, producer, and director Oliver Stone said he voted for Richard Nixon in 1968, based on his pledge to end the Vietnam War.
A major scene that was unable to be filmed was of Richard Nixon and his family watching Patton (1970), Nixon's favorite movie, and one he watched repeatedly. The scene would've highlighted Patton's speech at the beginning of this movie in which he says "Americans have never lost and will never lose a war, because the very thought of losing is hateful to Americans" which would have had resonance with Nixon's line "I will not be the first President to lose a war." But George C. Scott did not relinquish his image rights for Patton (1970), and the scene could not be filmed.
This movie was completed around the time Richard Nixon died in 1994. The footage of his funeral at the end, along with a narrated epilogue, was added several months before this movie's release.
While shooting the scene where Richard Nixon (Sir Anthony Hopkins) and Jack Jones (Larry Hagman) confront each other, the lights were aimed straight down at coffee tables in front of the fur upholstered couch. The lights were so powerful that the rug beneath one of the tables started smoking. In the middle of the first take, an extra noticed the increasing amount of smoke, and muttered "fire" quietly during a pause between lines of dialogue. James Woods (H.R. Haldeman) heard this and stopped the scene before the rug caught fire.