"As the only African-American on stage, I would like to speak. I do not believe you are a racist," Kamala Harris said to Joe Biden. "There was a little girl in California who was a part of the second class to integrate her public schools, and she was bused to school every day. And that little girl was me." - Sen. Kamala Harris addressing Joe Biden in the June 27, 2019 Democratic Party Primary Debate
Not only did Sen. Harris not call Biden a racist, but she even specifically said, "I do not believe you are a racist."
I don't think she will be Biden's running mate, however.