Inflation at long last is down. So are gas prices and Covid deaths and violent crime and illegal immigration. Unemployment remains near record lows. The economy, meanwhile, is growing, wages are climbing, consumer confidence is rising and the stock market is surging.

For President Biden, many of the numbers that define an administration are finally heading in the right direction. Except one: his approval rating.

Despite the flurry of good news on economic and other domestic fronts in recent weeks and months, Mr. Biden’s poll numbers remain low. Just 39 percent approved of his performance in the latest survey by The New York Times and Siena College, far from the level that would typically give strategists confidence heading into a re-election campaign.

An average of multiple recent polls by the website FiveThirtyEight puts Mr. Biden’s approval at 41.2 percent, lower than every president at this stage of their term in the last three-quarters of a century other than Jimmy Carter, who went on to lose his bid for a second term. The Times-Siena survey found Mr. Biden deadlocked at 43 percent to 43 percent with the Republican front-runner, former President Donald J. Trump, who has been indicted three times on criminal charges.

The question for Democrats is whether Mr. Biden’s public standing is a lagging indicator that will grow in the next several months as improving conditions in the country become more evident to voters, much as Presidents Ronald Reagan, Bill Clinton and Barack Obama were transformed from midterm losers to re-election winners. Or as some Democrats fear, is Mr. Biden’s anemic support more about Mr. Biden himself in a highly polarized moment that will make securing a second term next year vastly more challenging?

“Even though Biden’s numbers aren’t great, their trendlines, albeit halting, are positive, and we’ll see if they have a soft landing,” said Douglas B. Sosnik, who was Mr. Clinton’s White House counselor and analyzes today’s political trends in regular papers. “I feel like Biden has plenty of time to get the arrows in the right direction the way that Obama did and Clinton did and Reagan did.”

Biden aides express equanimity about the sluggish poll numbers, noting that Mr. Biden won in 2020 and that Democrats avoided a predicted “red wave” in 2022 despite his similarly low approval rating then.

But they are taking satisfaction for the moment that so many other indicators have turned positive. Given where this presidency began, in the throes of a pandemic and resulting economic crisis, it was hardly a given that a year out from the next election Mr. Biden would preside over a healthy economy and a healthy citizenry.

The president’s advisers argue that the positive trendlines of late were a direct result of Mr. Biden’s policies, including widespread Covid-19 vaccination, abundant pandemic relief spending, a mammoth new program to build or repair roads, bridges and other public works, record investments in clean energy and federal support to jump-start the semiconductor industry.

“What you’re seeing is the president put in two hard years of work of putting these policies in place, and they’re starting to deliver the results we thought they would,” said Ron Klain, the president’s first White House chief of staff, who managed many of those efforts.

“The good economic news is very important. It creates a base for him to run on,” he added. “I don’t think you’re ever going to persuade Republicans, but I think independents are coming around that the economy is doing better, and I think that’ll be a self-reinforcing cycle.”

Republicans will do all they can to foster the opposite impression, though, portraying the nation as a dystopian hellscape awash in crime, uncontrolled immigration, rising debt and economic misery. “Our country is going to hell,” Mr. Trump told supporters in April.

Mr. Biden has engaged in the battle of perceptions lately by branding the disparate elements of his agenda “Bidenomics” and embarking on a barnstorming tour of the country claiming credit for avoiding the recession experts had long predicted. His team has proved particularly disciplined in reinforcing that message with the kind of relentless repetition traditionally necessary to cut through the noise of public life.

Change in attitudes has been noticeable but incremental. Just 23 percent of Americans think the country is on the right track in the latest Times/Siena poll, but that is up from 13 percent a year ago. Similarly, just 20 percent consider the economy excellent or good, but that is up from 10 percent a year ago, while the share of respondents who called it poor has fallen from 58 percent last summer to 49 percent today.

It can take a while for the public perspective to catch up with improving conditions. A recession during the presidency of George H.W. Bush officially ended in 1991, long before the 1992 election, but it did not feel that way to voters who turned instead to Mr. Clinton and his “it’s-the-economy-stupid” campaign.

The Great Recession sparked by the 2008 financial crash formally ended in June 2009, but Mr. Obama’s Democrats were still swamped in midterm elections a year later. By the time he came up for re-election in 2012, public confidence in the economy had improved and he secured a second term.

Moreover, the lingering effects of recent hardships are not so easily erased. Inflation has fallen from a peak of 9 percent to 3 percent, a remarkable drop, but even though prices have stabilized, they have stabilized at a level still significantly higher than when Mr. Biden took office. Unemployment is at 3.5 percent, matching a half-century low and meaning that most people who want a job can find one, but not all of these positions have high pay with benefits. Wages have begun rising faster than inflation — but only just begun.

And for all that, conditions still feel in flux to many people. While illegal border crossings have dropped significantly since last year, they surged again in July. The S&P 500 stock market index has swelled by 17 percent this year, but slipped in recent days after the Fitch Ratings agency downgraded the U.S. government’s credit. Likewise, gas prices remain below their peak but have inched up lately.

What may prove more vexing to Mr. Biden and his strategists is the possibility that his political prospects may be decoupled from such issues. In past generations, Americans were more reactive to events in evaluating their presidents, while in recent years they have been more locked into their partisan corner. The days when a president could garner the support of 60 percent or more of the public feel long gone.

President George W. Bush’s approval rating in Gallup surveys fell below 50 percent two months after his second inauguration and never surpassed it again for his entire second term. Mr. Obama was below 50 percent for the vast bulk of his second term until his final months in office, and Mr. Trump never enjoyed the support of a majority of Americans for a single day of his presidency. Mr. Biden fell below 50 percent in his first summer in office and has yet to recover.

“Presidents today are less and less able to rely on even begrudging approval from partisans on the other side of the aisle,” said Kristen Soltis Anderson, a Republican pollster. “This places a lower and lower ceiling on presidential job approval, because without the ability to garner any approval from the other side, you are stuck relying solely on your own party’s voters to boost you.”

For decades, the American National Election Studies, a collaboration of Stanford University and the University of Michigan, has tracked how Americans felt about presidential candidates, asking them to rate them on a scale of zero to 100, with zero meaning very cool and 100 meaning very warmly.

It used to be that Americans had at least some respect or admiration for a candidate of the other party. In 1980, Democratic voters gave Mr. Reagan an average of 46.3 while Republicans gave Mr. Carter an average of 40.6. In 2000, Democratic voters gave the younger Mr. Bush an average of 44.8 while Republicans gave the Democrat Al Gore an average of 40.8.

But by recent years, views had hardened, becoming far more pronounced and partisan. In 2016, Democratic voters gave Mr. Trump just 14.5 while Republicans gave Hillary Clinton a 16.6. In 2020, Democrats gave Mr. Trump a 9.6 while Republicans gave Mr. Biden a 20.2.

“The reality is that presidents lately are not coming into office with even the slightest bit of good will or benefit of the doubt from the other side,” Ms. Anderson said, “and that places a very hard cap on how much approval they can ever hope to garner outside their own team.”

So as Mr. Biden and his team look ahead to 2024, they hope to make the most of an improving economy to bring home disaffected Democrats and independents, but they cannot count on a newfound swell of popularity to carry him to victory. Instead, they anticipate a grinding campaign in which they compete for a relatively small share of the electorate while trying to maximize turnout among their own voters.

“Republicans are just hard core,” Mr. Klain said. “They’re never going to approve of Joe Biden’s job, no matter what he’s doing. The vote is the vote. What matters is who’s going to win on Election Day.”