Joe Biden could feel himself losing the crowd — and along with it, the perception that he was politically unbeatable.

The voters watching wanted an apology. But Biden jabbered on about “de facto” versus “de jure” segregation in schools. He exploded into anger when accused of double talk.

“The audience kept pushing,” Biden would later reflect. “What they wanted was a full-out mea culpa and a hard statement … and I got hot.”

This wasn’t last month’s Democratic debate Biden was talking about, where he also mishandled a demand for an apology. It was an event 40 years earlier, an incident that still haunted Biden when he wrote about it in his 2007 memoir.

The crowd of hundreds of working-class voters were packed into the gymnasium of a suburban school outside Wilmington, Del. This crowd didn’t want him to apologize for fighting federally mandated busing, as Sen. Kamala Harris (D-Calif.) pushed him to do in Miami last month.

These constituents, like much of Delaware, were livid he wasn’t fighting the court-ordered school desegregation mandate harder.

Delaware’s racial division created hard political choices for Biden in the 1970s as he began his long political career. Today, nearly half a century later, some of the decisions he made then and the explanations he offered put him miles out of step with the party whose presidential nomination he seeks.

Biden likes to paint a portrait of Delaware as a harmonious collection of bedroom communities from which he catches the Amtrak into Washington. But the state was also a place where Jim Crow thrived not long before Biden hit the political stage.

When the U.S. Supreme Court outlawed school segregation in 1954, one of the five cases on which the justices ruled came from New Castle County, Del., where Biden won his first election 16 years later.

Just before Biden entered politics, the National Guard had kept the largely black city of Wilmington on lockdown for nine months in response to looting and racial violence that followed Martin Luther King Jr.’s assassination in 1968. The mayor repeatedly asked the governor to send the troops home, but the governor refused, keeping them there long after the National Guard had left other American cities facing similar tensions.

“America in 2019 is a very, very different place than the 1970s, and that’s a good thing,” Biden said last weekend. “I’ve witnessed an incredible amount of change in this nation, and I’ve worked to make that change happen. And yes, I’ve changed also.”

At the same time, however, Biden continues to hedge on disavowing the past statements on race, alliances with bigoted colleagues and anti-busing crusades that marked his early career. He argues that his lifetime achievements in advancing civil rights legislation and his partnership with President Obama should foreclose questions about his previous record.

“I will take his judgment about my record, my character, my ability to handle the job over anyone else’s,” he said, referring to Obama, during a speech in Sumter, S.C., on Saturday.

Biden’s opponents insist voters should consider his entire record. That record includes statements like this, which a 27-year-old Joe Biden made to the Wilmington News Journal after winning a seat on the New Castle County Council in 1970.

“I have friends on the far left, and they can justify to me the murder of a white deaf mute for a nickel by five colored guys,” he said. “They say black men had been oppressed and so on. But they can’t justify some Alabama farmers tar and feathering an old colored woman.”

He charged the ACLU would defend the black assailants, “but no one would go down to help the ‘rednecks.’ ”

At the time, Biden championed public housing that suburban towns tried to keep out, spoke proudly of working as a criminal defense attorney, and was a lifeguard at a pool where his was the only white face. But he also sent regular signals of empathy to white voters who told pollsters they believed government paid too much attention to blacks and that black Americans exaggerated the amount of prejudice they faced.

Biden tempered his liberal agenda with stands palatable to whites anxious over the pace of integration.

“Everybody’s opposed to public housing — no one wants it in their backyard, but dammit, if you have a moral obligation, provide it — but spread the load around,” he said in 1970 while pushing his plan for small clusters of affordable housing.

Very quickly, the flailing Democratic Party in Delaware saw the young councilman as their only hope for displacing incumbent Republican Sen. Cale Boggs, who had won his every statewide election for decades.

Biden began taking shots at busing. Civil rights activists were pushing to expand it in a state that had only slowly desegregated its schools, leaving many black children trapped in woefully inadequate classrooms.

By 1973, when Biden began his first Senate term, Wilmington’s public school population was nearly 90% nonwhite and 86% of third-graders could not read at grade level.

“It was horrible,” said Jeffrey Raffel, a University of Delaware professor who at the time was recruited to help the school systems establish a busing plan. In some classrooms that researchers observed, he said, “there was no learning taking place.”

Raffel, now an emeritus professor at the university’s Biden School of Public Policy and Administration, also happened to be one of Biden’s early pollsters. He said the senator was in a tough bind.

“Parents of kids in suburban public schools were over 90% opposed to moving kids across city-suburban lines,” he said. “Even in Wilmington, only 40% were in favor.”

Biden didn’t fight them. He insisted that sending kids in buses across district lines wouldn’t help. “Racial balance in and of itself means nothing” for education, he declared in his 1972 Senate race.

The positioning played well with suburban whites who, Biden would later write, “were terrified their children would be shipped into the toughest neighborhoods in Wilmington.” It may have also appealed to a faction of black parents who, as Biden argued, “were terrified their children would be targets of violence in the suburban schools.”

Busing would come to overshadow everything else on Biden’s agenda — and imperil his political career.

Soon after he reached the Senate, a far-reaching court order — one of the most sweeping of the era — roiled the state. The order directed officials to implement mandatory busing not just within school district boundaries, but across district lines in a large region that included Wilmington and 10 predominantly white, suburban districts.

“I could not walk into a grocery store or a restaurant in the northern part of Delaware without getting an earful,” Biden wrote in his 2007 book “Promises to Keep.” He recalled a white mother approaching him at an annual Chicken Festival and ordering her two boys to take a good look at the lawmaker:

“This is the man who has ruined your life,” she declared. “It’s because of him you’re going to be bused.”

Biden began working in the Senate against busing with a ferocity that some civil rights leaders still resent. His argument that the concept was “bankrupt” was accompanied by remarks through the 1970s that resembled statements made by some Southern opponents of integration.

“The new integration plans being offered are really just quota systems to assure a certain number of blacks, Chicanos or whatever in each school,” he said in a 1975 interview recently unearthed by the Washington Post.

“That, to me, is the most racist concept you can come up with; what it says is, ‘in order for your child with curly black hair, brown eyes and dark skin to be able to learn anything, he needs to sit next to my blond-haired, blue-eyed son.’ That’s racist! Who the hell do we think we are, that the only way a black man or woman can learn is if they rub shoulders with my white child?”

In an interview with NPR at the time, Biden presented his pitch for making anti-busing attractive to liberals.

“It has been an issue that has been in the hands of the racist,” he said. “And we liberals have out of hand rejected it because, if George Wallace is for it, it must be bad. And so we haven’t really looked at it.”

The federal government should instead be pursuing greater investment in black communities and expansion of opportunities, Biden argued.

By 1977, a lobbyist for the NAACP at a Washington hearing accused Biden of being motivated by racism. Biden responded angrily. “The first time I disagree with the civil rights people on an issue of substance, the question of racism is raised,” he responded.

Although Biden has sought to distance himself from some of the alliances with Southern senators who joined him, he has never dropped his view that busing would be ineffective.

Ironically, Raffel notes, his own state’s experience indicates otherwise. Busing happened in the Wilmington region regardless of Biden’s opposition, and by the measures of Raffel and several other academics, it was one of the most successful integration programs of the era.

“Delaware became one of the states with the most desegregated schools in the country,” Raffel said.