They should have titled this film All The President's Meta, because All the President's Men is…meta. Mega meta.
It's a story about two no-name reporters exposing a scandal. By doing so, the reporters become famous, maybe even more famous than the stars portraying them. And the newsmakers become the news.
But it's a miracle the film was any good, because the writing process was about as far from smooth as it can get. William Goldman, who wrote Butch Cassidy and the Sundance Kid, turned in a script that one journalist called "appalling."
Redford asked Bernstein for suggestions, and Bernstein had then-girlfriend Nora Ephron re-write the script. (Alternate title: Sleepless in the White House.) Redford called it "sophomoric." (Source)
This led director Alan J. Pakula and Redford themselves to re-write the whole script. The two men didn't mention they performed the re-write, likely because that would cause people to be nervous about the shaky nature of the film. Because of this, Goldman is not just credited with writing it—even though his entire script was thrown out—he won the Academy Award for it.
Redford was "blown away" that Goldman actually accepted it. It's like if you were doing a group diorama for school, and your diorama was so bad that the rest of the group threw out everything but the shoebox, but you still got an A. (Source)
However, Goldman would go on to actually write (as far as we know) many more films, including Misery, Chaplin, and Maverick. He also wrote The Princess Bride novel and screenplay. His success makes the drama around All the President's Men seem inconceivable.