WASHINGTON (AP) — Sitting in the Oval Office behind the iconic Resolute desk in 2022, an animated President Joe Biden described the challenge of leading a psychologically traumatized nation.

The United States had endured a life-altering pandemic. There was a jarring burst of inflation and now global conflict with Russia invading Ukraine, as well as the persistent threat to democracy he felt Donald Trump posed.

How could Biden possibly heal that collective trauma?

"Be confident," he said emphatically in an interview with The Associated Press. "Be confident. Because I am confident."

But in the ensuing two years, the confidence Biden hoped to instill steadily waned. When the 81-year-old Democratic president showed his age in a disastrous debate against Trump in June, he lost the benefit of the doubt and on Sunday withdrew as his party's nominee.

In the aftermath of the debate, Democrats who had been united in their resolve to prevent another Trump term suddenly fractured, and Republicans, beset by chaos in Congress and the former president's criminal conviction, improbably coalesced in defiant unity.

Biden never figured out how to inspire the world's most powerful country to believe in itself, let alone in him.

He lost the confidence of supporters in the 90-minute debate with Trump, even if pride initially prompted him to override the fears of lawmakers, party elders and donors who were nudging him to drop out. Then Trump survived an assassination attempt in Pennsylvania, and, as if on cue, pumped his fist in strength. Biden, while campaigning in Las Vegas, tested positive for the coronavirus on Wednesday and retreated to his Delaware beach house to recover.

The events of the last three weeks led to an exit Biden never wanted, but Democrats felt it was essential to maximize their chance of winning in November.

Biden seems to have badly misread the breadth of his support. While many Democrats had deep admiration for the president personally, they did not have the same affection for him politically.

Douglas Brinkley, a historian at Rice University, said Biden arrived as a reprieve for a nation exhausted by Trump and the pandemic.

"He was a perfect person for that moment," said Brinkley, noting that Biden proved in era of polarization that bipartisan lawmaking was still possible. Yet voters viewed him as a placeholder, and he could never transcend the text of his speeches to visually "embody the spirit of the nation with a sense of verve, energy and optimism."

As his reelection campaign entered its final days, Biden was still trying to prove himself and rally voters around fears that Trump would doom American democracy.

There was never a "Joe Biden Democrat" like there was a "Reagan Republican." He did not have adoring, movement-style followers, as did Barack Obama or John F. Kennedy. He was not a generational candidate like Bill Clinton. The only barrier-breaking dimension to his election was the fact that he was the oldest person ever elected president.

While he contemplated being in the Oval Office repeatedly from his perch as a senator from Delaware, voters rejected him again and again.

His first run for the White House, in the 1988 cycle, ended with self-inflicted wounds stemming from plagiarism, and he didn't make it to the first nominating contest. When he ran in 2008, he dropped out after the Iowa caucuses, where he won less than 1% of the vote. In 2016, Obama counseled him not to run, even though he was Obama's vice president. A Biden victory in 2020 seemed implausible when he finished fourth in Iowa and fifth in New Hampshire before a dramatic rebound in South Carolina.

He won the nomination and then did something rare in American politics: He defeated an incumbent president, Trump, who had been a catalyst for a seething sense of polarization. He then had to withstand the Jan. 6, 2021, assault on the U.S. Capitol by Trump supporters who falsely claimed that the 2020 election had been stolen.

David Axelrod, a former senior adviser to Obama, said history would treat Biden kinder than voters had, not just because of his legislative achievements but because he defeated Trump.

"His legacy is significant beyond all his many accomplishments," Axelrod said. "He will always be the man who stepped up and defeated a president who placed himself above our democracy.

"That, alone, is an historic accomplishment."

But Biden could not overcome his age. And when he showed frailty in his steps and his speech, there was no foundation of supporters that could stand by him. It was a humbling end to a half-century career in politics, yet hardly reflective of the full legacy of his time in the White House.

His record includes legislation that will rebuild the country in ways that will likely be seen over the next dozen years, even if voters did not immediately appreciate it.

"It takes time for it to happen," Biden told BET News on Tuesday. But in that same interview, he also demonstrated why the calls for him to step aside had grown so much louder: He was unable to recall the name of his defense secretary, Lloyd Austin, referring to him as the "Black man."

Those recent episodes stand in stark contrast to a list of accomplishments most presidents would envy and use as a sturdy foundation for reelection. The optimism about the country's future that Biden says drove him might materialize following his departure from the national stage.

Harvard University economist Jason Furman, a top aide during the Obama administration, said Biden "came into office when the economy was in the throes of COVID and helped to oversee the transition out of it to an economy that is now growing faster than any of its peer economies, with less inflation than they have."

Furman noted that Biden increased spending to make longer-term investments in the economy while keeping Jerome Powell as the Federal Reserve chairman, giving the Fed cover to hike rates and bring down inflation without disrupting the labor market.

In March 2021, Biden launched $1.9 trillion in pandemic aid, creating a series of new programs that temporarily halved child poverty, halted evictions and contributed to the addition of 15.7 million jobs. But inflation began to rise shortly thereafter. Biden's approval rating as measured by the AP-NORC Center for Public Affairs Research fell from 61% to 39% as of June.

He followed up with a series of executive actions to unsnarl global supply chains and a $1 trillion bipartisan infrastructure package that not only replaced aging infrastructure but improved internet access and prepared communities to withstand climate change.

But the infrastructure bill also revealed the challenge Biden faced in getting the public to recognize his achievement because many of the projects will take decades to complete.

In 2022, Biden and his fellow Democrats followed up with two measures that reinvigorated the future of U.S. manufacturing.

The CHIPS and Science Act provided $52 billion to build factories and create institutions to make computer chips domestically, ensuring that the U.S. would have access to the most advanced semiconductors needed to power economic growth and maintain national security. There was also the Inflation Reduction Act, which provided incentives to shift away from fossil fuels and enabled Medicare to negotiate drug prices.

Biden also sought to compete more aggressively with China and rebuild alliances such as NATO. He completed the U.S. withdrawal from Afghanistan that resulted in the death of 13 U.S. service members, an effort that was widely criticized. The president also faced criticism over his handling of the southern border with Mexico as illegal border crossings led to concerns about his handling of immigration.

He also found himself embroiled in a series of global conflicts that exposed further domestic divisions.

Russia's invasion of Ukraine in early 2022 worsened inflation as Trump and other Republicans questioned the value of military aid to the Ukrainians. Hamas' Oct. 7, 2023, attack in Israel sparked a war that showed divisions within the Democratic party over whether the United States should continue to support Israel as tens of thousands of Palestinians died in months of counterattacks.

Biden privately lectured aides to focus not on differences when listening to the public but to search for agreement. He hewed to the ideal of bipartisanship even when Democrats broke with the GOP.

And yet, just days before he dropped out of the race, Biden felt that his work was not done and his legacy incomplete.

"I've got to finish this job," he told reporters after a NATO summit.

But the size of the stakes and the fear of a Biden loss resulted in a bet by Democrats that the tasks he began could best be completed by a younger generation.

"History will be kinder to him than voters were at the end," Axelrod said.