I understand what he's trying to say. He didn't agree with them but they were civil and respected each other. But I think it was a mistake to mention segregationist specially. The situation looks worse for him when you look back at his record for opposing desegregation. And with the Democratic base becoming more progressive and less tolerant towards the establishment and the status quo Biden really needs to watch what he says.
I could see Kamala Harris getting a nice attack on Biden for this on the debate stage.
Biden has such a record?