WASHINGTON: Shortly after President Joe Biden's halting debate with Donald Trump on June 27, his exit from the 2024 U.S. presidential race seemed all but inevitable to some longtime allies.

Donors called it a disaster and held frantic calls to discuss next steps. Newspaper columnists demanded he bow out. Some Democratic lawmakers said plainly their party leader must step aside.

Two weeks later, Biden hasn't budged.

While acknowledging that at 81, he is no longer a young man and blaming exhaustion for his performance, he failed in a defiant follow-up televised interview to quell concerns it was more than just one bad debate night.

More Democrats are expected to ask Biden to leave the race in coming days. For now, the White House says it plans to "turn the page" on the incident, despite some opinion polls showing Trump's lead widening and swing states leaning Republican.

Why is Biden ignoring fellow Democrats and insisting he will beat Trump, 78, in the Nov. 5 election?

The reasons range from the deeply personal to party politics, interviews with more Democratic officials, aides, strategists and donors show.

BIDEN BELIEVES IN BIDEN

Biden's decision to run for reelection in the first place, despite his age, centered around his belief that he was the best Democratic candidate to defeat Trump, officials and allies told Reuters at the time.

Biden was skeptical about the ability of his vice president, Kamala Harris, to win over middle-of-the road voters, especially in critical swing states, and also of the ability of any of the deep bench of Democratic governors and lawmakers who are likely to be the party's future leaders, these sources said.

Explaining his decision to stay the course, Biden told George Stephanopoulos of ABC News last week: "I'm the most qualified person to beat him (Trump)." He later added that only the "Lord almighty" could convince him differently.

A defining principle of Biden's grief-stricken personal life and long political career has been perseverance, which he says he learned from his parents.

"My dad, who fell on hard times, always told me, though, 'Champ, when you get knocked down, get up. Get up," he told the 2008 Democratic National Convention when he accepted the nomination as Barack Obama's running mate.

He said his mother taught him: "Failure at some point in your life is inevitable, but giving up is unforgivable."

Actor George Clooney echoed the concerns of many Democrats about this principle, writing in a New York Times opinion piece on Wednesday that it was time for Biden to leave the race. Clooney said that "the one battle he cannot win is the fight against time. None of us can."

BIDEN'S CLOSEST AIDES ARE DUG IN

Biden's inner circle of top aides has reinforced his determination to hold on, according to sources close to them.

Biden has surrounded himself for decades with a small cadre of senior aides, such as political adviser Mike Donilon, counselor Steve Ricchetti, and deputy chief of staff Bruce Reed, who have steered him through previous crises and urged him to hang on.

That dynamic has only been amplified since the fallout from the debate.

"I have heard that Steve and Bruce and Mike are more dug in than he is," said one former Biden aide with ties to the White House. "They have grown roots and are not moving."

A White House official confirmed that characterization and said the dug-in approach applied to Biden's full senior staff.

Many of his aides, including senior adviser Anita Dunn, reinforce a sense of grievance and resolve around Biden: that he has been treated unfairly by the media, that he does not get the credit he deserves for toppling Trump in 2020, and that he has been underestimated before and proven his critics wrong.

Many people in Biden's orbit feel that way, the White House official said.

A memo circulated on Thursday by Jen O'Malley Dillon and Julie Chavez Rodriguez, Biden's campaign chair and manager, respectively, said there was no better alternative to Biden.

"Surveys do not take into account the negative media environment that any Democratic nominee will encounter. The only Democratic candidate for whom this is already baked in is President Biden," they wrote.

SOME DEMOCRATS FEAR CHANCES WITH HARRIS

Biden's ability to beat back Democratic calls for him to exit the race may have less to do with his own candidacy than the lackluster feeling some Democrats have about the potential alternatives to replace him.

In interviews, about a dozen Democrats, including elected officials and activists, many of them in the battleground state of Pennsylvania, all expressed deep concerns about Biden's mental fitness and ability to beat Trump.

But they also had little trust in a bench of Democrats led by Harris.

If Biden were to step down, they believe the party could not bypass Harris - the nation's first Black vice president and first woman vice president - without risking the diverse coalition needed to win the White House.

"It has to be Harris and I don't think that puts us in a better position to win than with a hobbled Joe Biden," said one senior Democrat in Pennsylvania.

On the other hand, some Democrats say Harris could bring new enthusiasm to the party and reenergize youth and Black voters.

CONGRESS FEARS AND TRADITIONS

Soon after Biden's debate, the leaders of both the Congressional Black Caucus and the Congressional Hispanic Caucus issued statements of support for Biden, which appeared to slow the trickle of criticism.

With their endorsement, rank-and-file Democrats were hard-pressed this week to publicly abandon Biden.

As of Thursday, only 11 of the 213 Democrats in the House of Representatives and one of the Senate's 51 Democrats had appealed to the president to withdraw from the race.

But multiple House members said they believed there was more to come, noting that they were expecting Democratic Minority Leader Hakeem Jeffries to pass on the criticisms from within the party to Biden.

"I wish more people were less scared," said Democratic Representative Seth Moulton, one of the House members who have called for Biden to end his campaign.

 - Reuters