The Inauguration

[Liquid]

Who was the first on-screen black president?

I know Morgan Freeman (who else!) played the president in the film Deep Impact.

That's the earliest I can find thus far...

After searching around, I also found a few sites talking about how the guy who played 'David Palmer' in 24 Hours supposedly modeled his character after Obama. Wouldn't that have had to be before he even talked about running for President though?

There are Many examples, most notably:
President Lindberg (Tommy 'Tiny' Lister) in The Fifth Element
Chris Rock in Head of State
Terry Crews plays President Camacho in Idiocracy
Morgan Freeman in Deep Impact

BUT the oldest is The Man from 1972. When the President and Speaker of the House are killed in a building collapse, and the Vice-President declines the office due to age and ill-health, Senate President pro tempore Douglas Dilman (James Earl Jones) suddenly becomes the first black man to occupy the Oval Office.