At the event, Mr. Biden noted that he served with the late Senators James O. Eastland of Mississippi and Herman Talmadge of Georgia, both Democrats who were staunch opponents of desegregation. Mr. Eastland was the powerful chair of the Senate Judiciary Committee when Mr. Biden entered the chamber in 1973.

“I was in a caucus with James O. Eastland,” Mr. Biden said, slipping briefly into a Southern accent, according to a pool report from the fund-raiser. “He never called me ‘boy,’ he always called me ‘son.’”

He called Mr. Talmadge “one of the meanest guys I ever knew, you go down the list of all these guys.”

“Well guess what?” Mr. Biden continued. “At least there was some civility. We got things done. We didn’t agree on much of anything. We got things done. We got it finished. But today you look at the other side and you’re the enemy. Not the opposition, the enemy. We don’t talk to each other anymore.”