Mann had a wealth of material to choose from. But his decision to make the "Rumble in the Jungle" the climax doesn't work. If you know Ali's life -- as most of the people who'll want to see this movie do -- then there's no suspense to it. He buries a much more important turning point-- Ali winning his case before the Supreme Court.
Today's Supremes would doubtless hand him over to a Military Tribunal to be executed by firing squad.
To anyone who lived through those early years, and remembers the impact young Cassius Clay had African-American life in this culture, there's some real fun to be had here. But not as much fun as William Kelin's great documentary of the real Ali, "Cassius le Grand."