Political movies are typically movies specifically for their times. Wag the Dog (1997, also starring Dustin Hoffman), was closely tied to the Clinton administration. Primary Colors is…also about Bill Clinton. And Babe: Pig in the City is about communism.
You know what they say: you can take the pig out of the city, but you can't take the communist out of the pig.
In other words, you can't separate political flicks from their ideologies, making these movies very divisive. A movie with Democratic ideology will turn off Republicans, and vice versa. But by making All the President's Men less about politics and more about uncovering corruption, the film was a success, and one that is still respected today for its story of two underdogs exposing a national scandal. (Source)
The film helped further the celebrity status of reporters Woodward and Bernstein, whose book was already a national success. Woodward still writes about the scandal, publishing The Last of the President's Men in 2015. At least until he finds another president's man and publishes The President's Barista: One More President's Man, the Last One, I Swear.