DETROIT — Joe Biden expressed surprise his political rivals were so critical of former President Barack Obama during the second round of 2020 Democratic presidential primary debates in Detroit, vowing to finish the work his old boss started with healthcare.

“I must tell you, I was a little surprised at how much incoming was about Barack, about the president. I’m proud to have served with him, and I’m proud of the job he did. I don’t think there’s anything he has to apologize for,” Obama’s two-term vice president told reporters Thursday outside the Detroit One Coney Island Restaurant.