Joe Biden said that he wasn’t prepared for Kamala Harris to attack him during the first Democratic presidential debate on his opposition to federally mandated busing in the 1970s.

“I was prepared for them to come after me, but I wasn’t prepared for the person coming at me the way she came at me,” Biden said in an interview that aired Friday, adding that Harris knew his late son, Beau Biden. “She knew Beau, she knows me.”