If Muhammad Ali had managed to beat Ken Norton in the first fight, who would have been the next viable contender for him to fight, and could the Ali-Foreman fight been made much sooner?
Assuming Ali did not sustain a broken jaw in this victory, I believe he would have done the same thing he did after winning the Norton rematch - clamor for a fight with Joe Frazier. Frazier's bout with Bugner was still future at the time of the first Norton fight, but he wanted to fight Frazier to (1) avenge his FOTC defeat, and (2) use a rematch with Frazier as a measuring stick for preparing for Foreman. If he could have secured himself as an opponent for Frazier instead of Bugner, he would be thinking that Frazier would be most vulnerable at that time, physically and psychologically, after suffering the devastating Foreman stoppage and before he could rebound with a victorious bout. However, I believe the Frazier people would have still wanted a tuneup before an Ali rematch. Even so, the rematch could have taken place sooner, and consequently the Foreman fight could have happened sooner. But 'could have' and 'would have' are two different matters. I think the Foreman camp would have delayed the Ali fight to around the time it actually did take place, figuring Foreman needed more seasoning while Ali got a little older.
