Former Vice President Joe Biden on Friday afternoon sought to defend his record following a searing exchange with Kamala Harris during Thursday evening’s Democratic primary debate.

“I heard and I listened to and I respect Sen. Harris,” Biden said at a Chicago labor luncheon held by the Rainbow PUSH Coalition. But we all know that 30 seconds to 60 seconds on a campaign debate exchange can’t do justice to a lifetime commitment to civil rights.” During that exchange, Harris questioned Biden’s record on bussing policies and praise for segregationist lawmakers.

“I never, never, never ever opposed voluntary busing,” Biden said on Friday, launching into a defense of a record that included his time in the Obama administration. “Folks, the discussion in this race shouldn’t be about the past,’’ he continued.