Joe Biden fondly recalled working with Democratic segregationists in the Senate to get things done, not because this is a riff that makes any sense in today’s Democratic Party, but presumably because he’s said it (or thought it) for a long time and old dogs and new tricks and all that. Cory Booker is calling on him to apologize and it’s certainly something Biden will have to clean up, the latest episode in what will surely be an ongoing series.