Biden didn’t help himself by cracking that Eastland always called him “son” and not “boy.” (“You just don’t joke about calling black men ‘boys,’’’ as Booker noted). Nor did he further his cause by insisting that it was Booker who owed him an apology, because “he knows better. There’s not a racist bone in my body.” As Donald Trump could tell you, any politician who feels compelled to offer such a defense has already lost the argument.

David A. Graham: Biden’s gaffe exposed the crack in his coalition

But the perpetual-outrage industrial complex that passes for modern politics obscures a difficult truth about Biden’s remarks: However infelicitous they were—and they were—they sprang from Biden’s deep personal experience, reflecting a lingua franca that may be close to a half-century old but is hardwired into his very being. How much that will hurt him in the political climate of 2020 is an open question, but there’s little doubt of his sincerity. When Biden arrived in Washington, as he wrote in his memoir, even “as they lost their grip on the nation, the southern Democrats tightened their hold on the Senate,” occupying the chairs of virtually all the major committees. Working with them, as Biden and many liberals of his generation did, was not a matter of artificial comity or keeping peace in the valley; it was the only way they saw to do their jobs in Congress. Understanding this context might help voters get inside the former vice president’s head, even if they, like his campaign opponents, recoil at his association with segregationists.

“I remember feeling that day like I was playing high school football again and I’d just taken my first tough hit of the season,” Biden wrote of his inaugural tangle with Eastland. “Now I had to prove I wasn’t going to stay down.” But Biden badly wanted a seat on the Judiciary Committee, so he decided to court Eastland, even though “he was as far apart from me on civil rights as any man in the Senate.” In fact, Biden wasn’t so far apart from Eastland on every issue: Like the Mississippian, he opposed the use of busing to integrate public schools, as well as the legalization of marijuana and amnesty for Vietnam-draft evaders—all of which were mainstream Democratic positions in their day.

By the end of Biden’s first term, in 1978, Eastland had agreed to give him a seat on the Judiciary Committee, and to come to Delaware to stump for his reelection. “I’ll campaign for ya or against ya, Joe,” he promised, “whichever way you think helps you the most.”

Biden was far from the only young Democrat to work with Eastland. When Ted Kennedy arrived in the Senate in 1962 from Massachusetts, one of his first visits was to Eastland, to discuss the committee and subcommittee assignments he coveted—panels dealing with immigration, civil rights, and the Constitution. Eastland said he’d oblige, if Kennedy would down the stiff scotch on the rocks that Eastland had poured for him that late morning. When Eastland turned his back momentarily, Kennedy took the opportunity to dump a good portion of the drink into the chairman’s potted plants.