This is the sixth installment in “Battle Tested,” a series analyzing early campaigns of some Democrats seeking the 2020 presidential nomination. Earlier pieces focused on Sen. Kirsten Gillibrand, Sen. Cory Booker, South Bend, Indiana, Mayor Pete Buttigieg, Sen. Kamala Harris and Sen. Elizabeth Warren.

Joe Biden was an unknown lawyer in his first term on the New Castle County Council when he started talking to people about his next move.

Just 29 years old, Biden wanted to launch a long-shot challenge in 1972 to Republican Sen. Caleb Boggs, one of the most popular politicians in Delaware history.

He asked the county councilman who had first encouraged him to enter public office. And the county aide versed in the arcane zoning issues that frequently arose on the council agenda. And anyone who had been around long enough to know his odds. They each gave him a version of the same answer.

“I told him, ‘You’re crazy,’” Vince D’Anna, the onetime county aide, said in a recent interview.

A lifetime before he became a front-runner in the crowded 2020 presidential field that will debate onstage Thursday night in Houston, Biden was the unknown and untested newcomer, betting that voters’ appetite for change was strong enough to overcome the overwhelming obstacles lined up against him.

He narrowly pulled off what was considered one of the biggest electoral upsets in Senate history. But that victory was quickly overshadowed. Just over a month after Election Day, his young wife, Neilia — who had played a central role in the campaign — was killed in an auto accident with his infant daughter, Naomi.

[How Elizabeth Warren learned to be a candidate]

The aura of tragedy that has since been associated with Biden’s career has extended to his reputation as a campaigner whose career-long ambition to ascend to the presidency has as yet remained just beyond his reach.

As he seeks the 2020 nomination, he has been dogged by questions of whether he is too old, too gaffe-prone, and too out of touch with the current mood of the Democratic Party.

But Democrats, Republicans and political journalists who encountered Biden during his first Senate campaign said they saw no hint of such questions in the race that launched him into the national mindset.

“He is an incredible campaigner,” D’Anna said. “He had a tremendous amount of energy and drive, and that’s what won the campaign.”

From recruiter to candidate

Biden, whose campaign did not make him available for an interview, wrote in his first autobiography, “Promises to Keep,” that he became captivated by the idea of politics at a young age. His inspirations were John and Bobby Kennedy and Martin Luther King Jr.

Boggs, a World War II hero, former governor and House member, had been in office 29 years — as old as Biden was during the campaign.

Biden was initially tasked by state Democratic leaders to recruit someone to run against Boggs. No one wanted to. “The race looked unwinnable,” he wrote in his autobiography.

Not only was Boggs popular, Republicans dominated Delaware politics.

According to Biden’s account, two Democratic party elders came up with the idea that Biden should be the one to run at the state party convention in 1971. Biden wouldn’t turn 30 — old enough to take the seat — until the Nov. 20 after Election Day.

He pitched the idea to his family as a “risk-free” proposition. “I figured, even if I lost, people were going to say, ‘That’s a nice young guy,’” he wrote.

[When Kamala Harris lost on election night, but won three weeks later]

But Biden saw an opportunity few others recognized, said Roger Harrison, a grad school friend who dropped a marketing job at General Mills for the campaign.

“Joe had a sense of what he could accomplish that did not dovetail with a lot of people who knew Delaware politics simply because Cale Boggs was just so popular,” Harrison said.

Biden saw the contrast he could bring to the race. “People looked at Boggs as someone who was very parochial,” Harrison said. “Joe was very dynamic. He had strong opinions on issues. He had an electric personality, and he seemed to enjoy, genuinely enjoy being a candidate.”

A family affair

The party was happy to have a challenger, but not enough to help the campaign financially.

With a shoestring budget, the Biden campaign became a family operation. His sister, Valerie, who ran his county council campaign, was manager and has played central roles in all his campaigns since. His brother James, a student at the University of Delaware, was in charge of fundraising. Frank, still in high school, recruited volunteers.

Neilia and his mother, Catherine, organized neighborhood coffees, similar to events deployed by the Kennedy family during John F. Kennedy’s 1946 Senate campaign. Neilia was her husband’s surrogate, charming southern ladies over her fried chicken recipes at the Sussex County chicken festival and the state fair.

The campaign hit the jackpot with the few professionals it could afford. Pollster Patrick Caddell and media consultant John Marttila would eventually become visionaries in their fields. But they were young and unknown in 1972, even as they helped craft what many observers said was a groundbreaking campaign.

“I’ve been doing this for almost 50 years, and people talk to me about campaigns: Senate campaigns, presidential campaigns, congressional campaigns, local representative campaigns,” said Ted Kaufman, who became friends with Biden while working on the race, then became his top aide and eventually was appointed to his Senate seat when Biden resigned to become vice president. “I have never seen a single one that can compare to the Biden ’72 campaign in terms of the size of the upset.”

Publicly, Biden undersold his prospects. “If I were a bookie, I’d give myself 5-to-1 odds right now that Boggs will be reelected,” he said when he declared his candidacy in January 1972, according to an account in Delaware journalist Celia Cohn’s book “Only in Delaware.”

[Opinion: Working with the enemy? Biden was just doing his job]

Picking up steam

In August, Caddell told Biden he had good news and bad news, Harrison recalled. The bad: Thirty-seven percent of people in the state knew who Biden was. The good: Of those who did know him, about 90 percent said they really liked him. All the campaign had to do was introduce him to more people.

He woke up early to shake hands with steelworkers as they arrived at work. He gave talks at high schools, telling aides that parents could be persuaded to vote for him if their kids came home with a good impression.

And the kids loved him. “It helped that he had more hair back then,” said journalist Curtis Wilkie, who covered Biden’s early career.

“The girls think he’s sexy and say so with little provocation,” journalist Norm Lockman wrote a few weeks before the election, according to an account in Slate. The young men, meanwhile, “get that ‘new hero’ look when Biden raps about how the old guard has bungled things.”

John Daniello, who had recruited Biden to run for the county council seat, said he at first thought the campaign was a long shot. But he came around when he saw Biden’s appeal — to the “cranky old guy” who ran the electricians union; the “big steelworker” who was international representative for the shops along the Delaware river; the poultry kingpins in the south.

“The more he got around and talked to some of the groups that were solid Democratic groups, unions, building trades in Delaware, auto workers were especially strong for him, that’s what helped in the beginning,” he said.

[Opinion: Biden’s path to 2020 is strewn with cautionary tales]

At the same time, Biden rolled out an aggressive media campaign. Most of Delaware was in the expensive Philadelphia ad market, putting television out of reach.

So the campaign recorded radio ads and produced fliers that maintained a tight focus on what Biden had defined as four core issues — the environment, taxes, opposition to the Vietnam War and crime.

The tabloid-style leaflets contrasted the youthful Biden with Boggs the veteran. Boggs’ generation wanted to conquer polio; Biden wanted to conquer heroin. Boggs wanted to make America safe from Stalin; Biden wanted to make America safe from criminals, Harrison recalled.

“I don’t think that was ever heard of in Delaware, that type of positioning, the use of words,” Harrison said. “We didn’t wander all over the track, and we kept focus on the issues.”

GOP takes notice

Donald R. Kirtley, who managed Boggs’ campaign, said the incumbent was an old-fashioned, laid-back campaigner who figured there was no reason to approach the race in 1972 any differently than the string of tough races he had won before. 

“Cale’s way of campaigning was just to drive around the state, in his own car,” Kirtley said. “He went to every fire hall, barbecue, VFW hall, American Legion Hall and shook hands with people. That was campaigning to him. He didn’t want any radio ads. He certainly didn’t want to spend big money on something like that.”

Still, the Boggs campaign didn’t recognize the threat until well after Labor Day, when Kirtley convinced Boggs to do polling.

The pollster flew in for a meeting when he got the results. “He said, ‘Don we’re in trouble,’” Kirtley recalled. “Whereas back in August or July, we were ahead 62 to 18 [percent], something like that, Joe had come up really rapidly in the two months leading to about the middle of October.”

Kirtley was sent to the White House to meet with President Richard Nixon, who had served in Congress with Boggs and was a friend. Nixon thought he had an easy fix.

“Get Cale over here,” the president said. “We’ll do a film of me and him walking around the Rose Garden, and I’ll say how important it is to have him in the U.S. Senate.” National Republicans helped the campaign raise several hundred thousand dollars, which it spent in the last month.

Democrats, meanwhile, awoke to Biden’s prospects and started pouring money into the state, Harrisson recalled.

As Boggs began flooding the state with fliers and advertisements, fate intervened. The Boggs campaign planned an insert in the Wilmington News Journal. It showed a picture of the moon with the caption, “The only thing Biden hasn’t promised you.”

But the newspaper was hit with a labor strike, and the state GOP had to deliver the fliers by hand, according to Cohen’s book.

On Election Day, Biden pulled off the upset, 50 percent to 49 percent, while Nixon was carrying Delaware by 20 points.

The margin was slim enough that any number of factors could have made a difference.

1972 was the first year after the voting age was lowered to 18, a boost to the youthful Biden. Delaware had done away with a lever that voters would pull to vote a straight ticket, making it easier for Biden to exploit his cross-party appeal. He also could have profited from the success of two other Democrats who won notable races that year, Gov. Sherman W. Tribbitt and Wilmington Mayor Thomas Maloney, who was 30 and often compared to Biden.

Whatever it was, Biden celebrated his victory and then his 30th birthday with his wife and children.

As he would later write in his autobiography, he was thinking, “The doors were about to swing open for the rest of our lives.”

Things did not go exactly to plan, as the automobile accident that claimed Neilia and Naomi made Biden face a stark choice over how much politics would define his life. But more than 40 years later, he’s still knocking on doors.