WASHINGTON — The most prominent national Democrat to campaign in person for Doug Jones was the one who has arguably known the senator-elect the longest: Former Vice President Joe Biden.

It was 41 years ago when a first-term senator from Delaware, just remarried, traveled to Alabama to deliver remarks at a Birmingham law school. Introducing Biden was Jones, just in his early 20s. A few years later, when Jones joined the staff of Alabama’s new U.S. Senator, Howell Heflin, he was assigned to work on his Judiciary Committee staff, reuniting him with Biden.

As both became more active in state and national politics, they stayed in close touch. When Biden waged his first campaign for the presidency in 1988, Jones served as his Alabama co-chairman. When Biden ran again in 2008, Jones helped raise money for his campaign and organized some events for him in southern states.

As Biden’s political career appeared to be ending in 2016, Jones began pondering his own candidacy. At first, he eyed what was expected to be an open governor's seat in Alabama in 2018. But when Alabama Sen. Jeff Sessions resigned his seat to become U.S. attorney general, he began considering congress instead.

Biden and other longtime aides, including his former chief counsel on the Judiciary Committee and a native Alabamian, Mark Gitenstein, encouraged him to make that race.

“I promised Doug I’d campaign for him or against him, whichever will help the most,” Biden joked when he did join Jones for a campaign rally in Birmingham in October.

Though Biden didn’t return in person, he stayed in touch with his colleague as his campaign against Roy Moore took shape. He recorded a robocall the campaign used in the race’s final hours as an improbable victory began to look in reach.

On Tuesday night Biden was in New York to receive an award from Sandy Hook Promise, just after the five year anniversary of the Newtown school massacre. As soon as he left the event he called Jones, according to an aide, to “buck him up” and ask how the night was proceeding.

When the race was called, Biden called again — a long-serving now-former senator, congratulating a longtime friend about to join the same body he long revered.