Few prominent Americans spoke as authentically as Martin Luther King. Still, even after winning a Nobel Peace Prize, he struggled to speak out publicly against the Vietnam War after he privately came to oppose it.
Today I’m sharing how Muhammad Ali led Martin Luther King, despite not being a statesman or politician. On the contrary, he simply spoke authentically—that is, without the filter many people use to keep from saying things they might regret. Ali had no relevant credentials. He only spoke with conviction. Even then he spoke simply, with nowhere near the depth or breadth that King later did. Anyone can speak so bluntly if they have the experience speaking authentically.
We may, today, forget the risks a public figure had to take then to oppose the United States government in wartime. At the time much of the nation intensely opposed their statements.

Martin Luther King’s speech was eloquent, well-reasoned, and rousing, though sharing the ambivalence he had to navigate to speak out. Here is a link to the speech’s text and audio of King speaking. Here is the Wikipedia page on the speech.
Here is Martin Luther King publicly supporting Muhammad Ali. Recall that Ali had joined the black Muslims, a group many Americans disliked and feared, meaning that supporting them risked his support.