In National Treasure (2004) Nicholas Cage explains this whole course
Birth of a Nation (1915) -- the first movie to have a White House screening, sadly revealing Woodrow Wilson's writings and racial attitudes in the early 20th century (at 2:42:50).
Gabriel Over the White House (1933) -- also illustrates the Trump approach to civil liberties.
Mr. Smith Goes to Washington (1939)
Mission to Moscow (1943) -- featuring Good Guy Stalin (at 45:00)
Duck and Cover (1951) -- civil defense documentary on saving yourself from the Bomb.
Fail-Safe (1964) -- after the Cuban Missile Crisis, a scary look at an accidental nuclear attack
Dr. Strangelove (1964) -- a satirical look at an accidental nuclear attack.
All the President's Men (1976) -- an iconic but made-up line.
The Distinguished Gentleman (1992) on money and politics