Lew Alcindor (right), who later changed his name to Kareem Abdul-Jabbar, alongside Bill Russell (left) and Cassius Clay (Muhammad Ali) in 1967. Bettmann Archive/GettyImages

It was crowded and euphoric inside San Francisco’s Herbst Theater at the War Memorial and Performing Arts Center on Tuesday, Aug. 30, as Kareem Abdul-Jabbar, the NBA’s leading all-time scorer and one of the most prominent athlete-activists in history, took center stage to discuss current politics and controversial issues affecting the United States.

Though remembered for his iconic “sky hook” shot and as an all-time great with the Los Angeles Lakers, the outspoken seven-foot-two-inch giant, Abdul-Jabbar, is a columnist for Time Magazine and The Washington Post, and an author of several books.

Playing professionally from 1969-1989, Abdul-Jabbar had one of the greatest careers in basketball history, with six NBA titles and three NCAA championships. His career was one rooted in activism from his collegiate days at the University of California Los Angeles. Activism is still something he engages in today.

Born Lew Alcindor, Abdul-Jabbar was raised in an era when, as an African American, he had few rights in the United States.

But it was the murder of Emmett Till in 1955 that forever changed his outlook on life. Till—a 14-year-old African-American teenager from Chicago visiting family in Mississippi—was lynched after talking to a white woman.

Kareem Abdul-Jabbar (right) signs a copy of his book for a young fan on Aug. 30 in San Francisco. Photo Alejandro Galicia-Díaz

“I couldn’t really understand it, and it really just made me focus my mind on: ‘What is this problem that causes somebody to get murdered like that?’” Abdul-Jabbar said at the Commonwealth Club. “I started paying attention immediately at that moment to what was going on in the Civil Rights movement.”

In an era when Jim Crow laws ruled the segregated south, Abdul-Jabbar witnessed the blatant racism in American society. Feeling the need to take a stand and contribute in some way to the elimination of the Jim Crow laws, he became an activist, boycotting the 1968 Olympics while still in college and converting to Islam. He would later change his name from Lew Alcindor to Kareem Abdul-Jabbar.

With the U.S. elections just a few months away, the 19-time NBA All-Star is trying to make a sense of Trump’s antics against Muslims and minorities.

“Mr. Trump is basically trying to use people’s fear and lack of understanding of what’s going on for votes by saying what he says and doing what he does,” Abdul-Jabbar said. “It’s putting Americans against each other.”

The former Laker also spoke about San Francisco 49ers quarterback Colin Kaepernick’s decision to sit down during the American national anthem.

“I think that what Colin was doing was trying to attract attention to an issue that is very important to him,” Abdul-Jabbar said. “What I saw that he said was he is fed up with the fact that too many young black people are dying at the hands of police, who are reacting to fear and their misunderstanding of people that they are supposed to protect and serve.”

Despite all of the negativity surrounding Kaepernick’s decision, Abdul-Jabbar says the quarterback’s decision is a worthy cause. For the basketball star, it’s important to protect the First Amendment because the right to free speech is the basis for what the United States is about.

After Abdul-Jabbar’s hour-long talk, he stayed on the stage to sign hundreds of people’s copies of his book, “Writings on the Wall: Searching for a New Equality Beyond Black and White,” and take pictures with his fans.