President Biden will lock arms with two of his Democratic predecessors at a campaign fund-raising event on Thursday evening in New York City, a public display of support from the two men who understand like few others what he faces.

Yet in one key way he will be standing alone.

Of the triumvirate of recent Democrats in the White House, Mr. Biden is the one who historians, political strategists and policy experts argue has racked up the most expansive list of legislative accomplishments — and has received the least amount of credit for them.

In a first term with a closely divided Congress, Mr. Biden signed legislation to provide $1.9 trillion in pandemic stimulus, $1 trillion in infrastructure spending and $370 billion to fight climate change, as well as the first gun control measures in 28 years. It is a roster of achievement that surpasses Bill Clinton and Barack Obama, the two Democratic former presidents who will join him on Thursday in New York. And yet Mr. Biden’s approval ratings are the lowest of all three men. While voters broadly support some of Mr. Biden’s key policies, they are far more pessimistic about the future. And they’re not confident in his ability to serve a second term.

“His biggest problem is not so much his ability to get things done, as we’ve seen, but his ability to put together a message that reaches the average American, no matter where they’re located, whether it’s a red state or a blue state, and to be able to get them to understand just exactly what he’s trying to do for the country,” Leon Panetta, who served as Mr. Clinton’s chief of staff and also in Mr. Obama’s cabinet, said of Mr. Biden.

That central political paradox reflects the unique circumstances of the Biden era.

Mr. Biden is running in a tumultuous political climate unlike any the country has experienced before in modern times, seeking re-election in the first presidential contest since the pandemic was a major threat, the Jan. 6 attack on the Capitol and the Supreme Court’s ruling overturning a half-century-old constitutional right to an abortion.

Mr. Biden’s predicament also highlights just how deeply Americans have lost faith in politics and government since Mr. Clinton and Mr. Obama were in office.

Rahm Emanuel, Mr. Obama’s first chief of staff who is now Mr. Biden’s ambassador to Japan, said presidents and American governments have never recovered the trust they had before the Iraq war and the 2008 financial crisis. Both were seen as seminal events by much of the public. Yet no public official was ever prosecuted for their involvement in either one, he added.

“The pre-Iraq war, pre-financial meltdown is one era and then Obama and Biden operate in another era,” Mr. Emanuel said.

Mr. Emanuel said he urged Mr. Obama to address financial reform before the health care law, in order to mete out what he called “Old Testament justice” to bankers to demonstrate the power of government. The president pursued health care instead.

The effects of that choice, Mr. Emanuel argued, remade American politics for years to come.

“Those two moments trigger a period of anger where the entire establishment earns the public’s resentment and distrust,” he said. “After that, you can’t give me any politics or politicians at the national level that really get credit.”

Of course, presidents rarely earn broad acclaim for accomplishments while they are still in office. There’s a pattern of presidential nostalgia that, with Mr. Trump on the ballot, has the potential to hurt Mr. Biden in November. Mr. Obama’s signature achievement, the health care law known as the Affordable Care Act, became more popular in the months after he left office, as Republicans tried repeatedly to repeal it.

“Gone are the days of Reagan or even Clinton where you can get credit,” said Jim Messina, who was the campaign manager for Mr. Obama’s re-election bid. “We’re just too polarized for that now.”

At times, there have been hints of competition between the three men. Mr. Obama casts Mr. Biden and his administration as “essentially finishing the job” of his presidency. (Mr. Biden has adopted “finish the job” as an occasional slogan for his own re-election campaign.)

But White House aides say Mr. Biden speaks to these two Democratic predecessors frequently, consulting both men about politics and policy — down to the detailed level of establishing campaign offices in key swing states. Their joint event on Thursday is intended as a show of solidarity from the standard-bearers of their party. The president and two former presidents will be interviewed by Stephen Colbert before an audience of about 5,000 people at Radio City Music Hall. The event, which aides pre-emptively claim is the “most successful political fund-raiser in American history,” is expected to raise more than $25 million.

Still, Mr. Biden remains unique among American presidents in how little credit he receives. As the economy has rebounded from pandemic lows, Mr. Biden gets poor marks for his handling of the issue, trailing below Mr. Obama, who took office during a historic downturn. Even on Mr. Biden’s strongest day, his approval rating has never matched the high points of either Mr. Clinton or Mr. Obama during their first terms. And a large share of his own party still harbors lingering concerns about whether he’s fit to serve another term.

Jennifer Palmieri, who worked in the Clinton and Obama White Houses, said Mr. Biden was not alone among world leaders in democracies where voters remain unsettled after the pandemic.

“There’s too much Dad is owning right now,” Ms. Palmieri said, referring to Mr. Biden as the nation’s father figure. “Dad is being blamed for a lot. He’s being held responsible for a lot of anxiety in people’s minds and I think we take it out on the president’s approval rating.”

Ranking the accomplishments of these three presidents — all of whom operated in different eras with different economies, foreign policy crises and cultural changes — is an inexact science. Beverly Gage, a professor of history and American studies at Yale University, said what is unique about Mr. Biden in particular is the sweeping approach he has taken to government.

Mr. Clinton ran as a centrist. He saw the path to help his party claw back into power after the Reagan years: rebranding Democrats as fiscally responsible and willing to take a more limited approach to government. His first-term accomplishments included passage of a crime bill, the Violence Against Women Act, and the Family and Medical Leave Act and creation of an early Head Start program.

When Mr. Obama came into office, he passed significant legislation, including the health care law and financial regulation, but did not totally abandon Mr. Clinton’s more centrist approach.

Mr. Biden, however, entered with a more “expansive embrace” of government, Ms. Gage argued, adding that he aimed to create an administration in the image of Franklin Delano Roosevelt, whose portrait he hung in a prominent spot in the Oval Office.

“He set out in a policy sense to be quite a different president than Clinton and even from Obama,” said Ms. Gage, who met with Mr. Biden in the White House in early January. “I do think of Biden as being very much more a president who looked back to moments like the New Deal and took them not as things to reject and run away from but as real models for what he was trying to do.”

White House officials say they are building on the work done by the previous administrations, noting that many of their staff worked in the Obama administration, including Mr. Biden’s chief of staff, Jeff Zients, as well as many of his senior aides and the president himself.

Gun control, officials said, offers an example.

In 1994, Mr. Clinton signed an assault weapons ban, which was shepherded through the Senate by Mr. Biden. After the 2012 mass shooting at Sandy Hook Elementary School in Connecticut, Mr. Biden led the Obama administration’s public efforts. Mr. Biden helped build new support for restrictions as vice president, even as Mr. Obama failed to win enough votes in the Senate to pass them into law. And as president, Mr. Biden ended the decades-old gridlock by signing a bipartisan gun bill in 2022.

Louisa Terrell, Mr. Biden’s former director of legislative affairs, described the work of the Obama administration as providing the policy scaffolding for much of what Mr. Biden pursued as president.

“We felt like we were building off the experiences and foundations that had been laid during the Obama administration and Clinton administration,” said Ms. Terrell, who also worked as a special assistant for legislative affairs in the Obama administration.

Donna Brazile, who worked on the 1996 Clinton campaign and later served as chairwoman of the Democratic National Committee, said Mr. Biden had “hit a triple” in his first term, but had struggled to convey the extent of his accomplishments to the country.

Like other Democratic leaders, she predicted that Mr. Biden’s political standing would increase in the fall, once more voters tune in to the campaign after the summer party conventions.

“You cannot lay out your recipe when people are not ready to eat,” she said. “Nor can you put a message out that supposedly resonates before people understand why it has meaning.”

Ruth Igielnik contributed reporting.