And one of those ironies of history that he is so beloved now. If you watch the fights before he was stripped of the championship for refusing the draft, he was regularly roundly and soundly booed by the audience, hated for his militancy and social activism. I think there was still hostility in the first few fights in the 70s after he was granted his fighting license again. But the world finally caught up with him. In the process of him becoming a beloved, public figure, though, there was something lost. Not because of him personally, but that's just the nature of public mythologizing, which tends to round over the rough edges. Like how MLK is often remembered now as a figure of hope and optimism (I Have a Dream), rather than the genuine challenge he was to the power structure through his activism on poverty and the Vietnam War.
One of the treats of Youtube is that you can go back and watch all his fights, especially the ones from the 60s, and see that lightning quick jab snap multiple times into the opponent's face with stunning effect, all while Ali is moving backwards!