A day after California Sen. Kamala Harris called out former Vice President Joe Biden during Thursday night’s presidential primary debate for his opposition in the ‘70s to busing, which helped to desegregate schools, Biden pushed back.

Harris’ comments on the debate stage caused some in the audience to reexamine Biden’s civil rights record. During the debate, Biden said he did not oppose busing across the board, but said he merely opposed the federal government’s control of it; a right, he said, that was better left up to local communities.

Biden appeared in Chicago Friday at the Chicago Teachers Union headquarters, 1901 W. Carroll Ave., to address Chicago’s black community during the International Rainbow PUSH Convention, and took his time, beyond the 30-second constraints of the debate stage to defend his civil rights career.

To clarify his position on busing in the ‘70s, Biden said he supported federal action to address the root causes of segregation, such as addressing the issue of redlining.

“I’ve always been in favor of using federal authority to overcome state initiated segregation,” Biden said. “It’s a constitutional question to protect the civil rights of every single American, and that’s always been my position. That’s why I ran for federal office in the first place.”

Back in President Barack Obama’s hometown, Biden touted Obama’s “backbone like a ramrod,” and added he was tired of people pointing out what their administration was not able to accomplish.

“The discussion in this race today, shouldn’t be about the past. We should be talking about how we can do better,” he said.

Biden turned the conversation of race to President Donald Trump, criticizing him for never condemning the violent white supremacists in Charlottesville, Virginia.

“I promise you, if I get elected president, I will be a president who stands against racism; [and for] the forces of inclusion and tolerance everywhere in society … [because] it matters what we say,” Biden said.

Before Biden’s remarks, the Rev. Jesse Jackson, founder of the Rainbow PUSH Coalition, said Harris was right to challenge state’s rights and that he plans to speak to Biden about busing.

“Joe Biden has strongly held beliefs,” Jackson said. “That doesn’t make him a bad guy.”

Meanwhile, New York Mayor Bill de Blasio is calling for an apology from Biden for his alignments with segregationist senators.

A handful of other Democratic presidential candidates are expected to make appearances at the convention’s events, scheduled through Tuesday, July 2, including Massachusetts Sen. Elizabeth Warren on Saturday; de Blasio on Monday; and Mayor of South Bend, Indiana, Pete Buttigieg on Tuesday.

Jackson founded Operation PUSH in the late 1960s. The civil and human rights organization is now known as the Rainbow PUSH Coalition. The organization is “dedicated to improving the economic conditions of black communities across the United States,” and is committed to social, economic and racial justice, as well as gender equality in communities across the country.