COLUMBIA, S.C. — Joe Biden flew here unexpectedly Tuesday night before New Hampshire votes were even counted, seeking to save his faltering campaign in a state he must win — and one where allies, voters, party officials and others say he remains a front-runner, albeit a wounded one.

After dismal showings in last week’s Iowa caucuses and then again Tuesday in the New Hampshire primary, the former vice president is now counting on what has so far been durable support from black voters who make up a large share of the Democratic electorate in South Carolina.

But some people close to the operation have grown worried that Biden is no longer a sure bet in this state’s Feb. 29 primary and that his uneven performances on the campaign trail could dampen support. Some who once saw Biden as the strongest potential challenger to President Trump are looking at others, including billionaire Mike Bloomberg, who won’t be on the ballot here but is competing in states that vote a few days later on Super Tuesday.

“Black voters in South Carolina really like Joe Biden, trust Joe Biden and respect Joe Biden,” said Steve Benjamin, the mayor of Columbia and a Bloomberg supporter. “But they are pragmatic and want to win and beat Trump. If your number one argument is electability, and you can’t crack the top four in two or three states in a row, that’s a tough argument to make.”

Biden’s biggest challenge in the state has come from billionaire Tom Steyer, who is also betting his campaign on a strong showing here. While Biden has been trying — and failing — elsewhere, Steyer has been blanketing South Carolina with ads and organization.

Asked whether Biden’s campaign is in trouble, Dick Harpootlian, a longtime Biden friend and fundraiser, paused for two seconds and leaned back in his chair before saying no. Biden had 30 years of experience in South Carolina and could remind voters how many times he’d been in the state, how much he cared about middle-class people and his role backing President Barack Obama, Harpootlian said.

“I don’t think it’s in trouble. But I do think they have to apply the resources and focus on South Carolina if they’re going to have the kind of win that sends a message,” he said. “They need to send more resources here to get the message out.”

Biden, addressing supporters here Tuesday night as New Hampshire results showed him running near the bottom of the field, portrayed South Carolina as friendlier political terrain for him — and more representative of the party.

“Up until now, we haven’t heard from the most committed constituency of the Democratic Party, the African American community,” he said.

This account of Biden’s increasingly important campaign in South Carolina is based on interviews with 39 party and campaign officials, activists, voters, political strategists and longtime political observers in the state, many of whom say Biden is underperforming.

His path to a potential resurrection here is further complicated by his surging rivals — Bernie Sanders and Pete Buttigieg — who want to show in South Carolina that they can broaden their support beyond heavily white constituencies.

And the impact South Carolina may have on the broader race remains unclear. Biden can ill afford another defeat in the Feb. 22 Nevada caucuses, which take place one week before the primary here, and the outcome here will be quickly swamped by Super Tuesday on March 3, when states including California, Texas and Virginia hold their primaries.

Biden has visited South Carolina eight times thus far, but aides say they expect a near-universal focus on the Palmetto State in upcoming weeks before the primary vote after his last-minute decision to speak there Tuesday night. The primary is heavily, though not entirely, African American and largely focused on the state’s bigger cities, such as Columbia, Orangeburg, Charleston and Greenville.

“The South Carolina primary will be one of the first contests in this process in which communities of color will have the opportunity to make their voices heard,” said Biden senior adviser Symone Sanders, “and our campaign has significantly increased its investments here, including with expanded television and radio ad buys covering the vast majority of the state’s population.”

On multiple fronts, Biden seems behind. He has 43 aides in South Carolina, a campaign spokeswoman said, while Steyer has 93, and Sanders has 72.

Steyer has spent more than $14 million on radio and television commercials in South Carolina. Biden recently went on the air for the first time last week, campaign and party officials say.

“We’ve seen more mail from Steyer than any candidate, times three,” said Benjamin, echoing a sentiment from others in the state. Others said they had received so much mail and watched so many Steyer ads that it is a joke in their households that you cannot escape him.

“Try to watch an REM video on YouTube without seeing him,” said Phil Bailey, a prominent Democratic consultant. “You can’t do it.”

David Bryant, a retired social worker from New York who lives in Columbia, said he was deciding between Steyer — whose name he at first struggled to recall — and Sanders. He said he liked Biden but had not seen a commercial from him or heard anything from his campaign, and he thought Biden, 77, lacked the vigor that some of the other candidates had.

“If I thought he really wanted it, he’d be my first choice,” Bryant said as he drove around Five Points, a bar district popular with college students. “Biden don’t seem to want it bad enough. He doesn’t seem like he really wanted it.”

While serving ham biscuits and cheddar grits to churchgoers at Lizard’s Thicket on Sunday, Joann Prince recounted calling Biden’s campaign office to volunteer. “But no one called me back,” she said.

Eventually, Prince said she went to the campaign office, where she was assigned to door-knock in a poorer part of Columbia. Prince, who is in her 70s, went alone, with a script to remind black voters that Biden was Obama’s vice president. Hardly anyone was home, she said, and most yards had signs warning of dogs.

“It was a disaster,” she said.

Prince said she still likes Biden, but after dealing with his campaign, she is considering other candidates. “I’m on the fence,” she said.

There were few signs for Biden in yards around Columbia, and a recent visit to the Columbia field office gave no indication of bustle.

Some party officials, lawmakers and strategists in Columbia say they have received little contact from Biden’s campaign.

Carol Fowler, a national Democratic committeewoman, said she had not received a call from Biden or his campaign asking for her support — though other candidates have called her. Some activists complained after Biden came to Abbeville to file his papers but did not meet with them.

“If I do endorse, it will probably be someone who has called and asked me,” she said, adding that Biden was still the favorite in South Carolina but seemed to be fading. “A lot of undecided voters are just looking for someone who can beat Trump, and they are maybe looking to New Hampshire and other states more than in previous years.”

Campaign officials and some Biden allies say he has been in the state for decades, raising money for local officials and representing Obama as his vice president. Benjamin, the Columbia mayor backing Bloomberg, and others lauded Kendall Corley, his campaign manager in the state, as one of the best political operatives in South Carolina. Biden has more than 100 pastors across the state who have endorsed him. His aides dismiss the other primaries as dominated by white liberal voters and activists — not the type where Biden necessarily does well.

State Sen. Marlon Kimpson, one of Biden’s most prominent backers, was dismissive of Steyer’s money and the notion that Biden’s campaign is eroding. “Even Ronald McDonald can move the needle with a billion dollars,” he said.

He added: “I think people are frustrated that [Iowa and New Hampshire], the first state that couldn’t even get the results counted, and the second, a very small state, are setting the narrative. Neither is representative of the electorate. We have to let the race play out.”

On a recent evening in Orangeburg, more than 500 people showed up to see Biden, eclipsing a similar Steyer event. Bernice Scott, a fierce Biden supporter who organizes door-knocking with 35 other women wearing shirts labeled “The Reckoning Crew,” said many black voters in South Carolina are not won over by Steyer or others.

“Everybody I talk to, they say, we know him, oh yeah, I’m supporting him,” said Scott, a councilwoman and local activist.

But the Steyer campaign has worried advisers like Amanda Alpert Loveday, who runs Biden’s super PAC in South Carolina and said Steyer’s “huge push into the state hurts because it eats into the margin.”

Activists and party officials say Steyer has visited South Carolina more than a dozen times, taking advantage of his foes focusing on other states.

Volunteers for the Biden campaign have been instructed to tell potential supporters that Steyer is a good Democrat but lacks experience.

Others close to Biden have taken a more aggressive tack in criticizing Steyer, accusing him of paying supporters for their endorsements. Scott said she found it insulting that candidates like Steyer are spending so much money in the state when they have no history there. “I can’t be bought, and I won’t be sold,” she said.

Harpootlian, Biden’s longtime friend and golf buddy, recently accused Jerry Govan, a state lawmaker, of endorsing Steyer only because he was paid $43,000 by the campaign. Filings show that Govan was paid that sum for consulting.

Steyer demanded an apology from Biden during Friday night’s debate, which Biden did not give, and Govan called the charge that he was backing Steyer for money offensive.

Harpootlian, a longtime bomb-thrower in the state, grinned on a recent morning when recounting the episode and his appearance in the debate. “I’m sorry for causing a distraction,” he said, when asked about Biden’s comments during the Friday debate that Harpootlian was sorry. “If they want to get in the weeds, I’m happy to get in the weeds with them.”

Meanwhile, Sanders has taken a different approach. Michael Wukela, a senior aide for the campaign, said Sanders is focused on places and issues where other candidates are not — a climate change town hall in Myrtle Beach, a Medicare-for-all breakfast in Florence and a visit to a shuttered hospital not far from Columbia.

“More and more, the people we talk to don’t like being taken for granted and somebody’s firewall,” Wukela said. “People are tired of the status quo.”

On a recent Monday, dozens of workers and volunteers were calling and plotting visits from the Sanders headquarters. A sign on the wall said the “Bernie 2020 Wish List” included folding chairs, water, juice, coffee, world peace, an espresso machine, snacks and Gatorade. The only item with a check mark was a microwave. The room looked like a College Democrats meeting.

Sipping a Bud Light on the back deck at the Salty Nut Cafe in downtown Columbia on Monday afternoon, Loveday, who leads the Biden super PAC, seemed largely untroubled. He could beat Trump. He could win South Carolina. Voters are too “conservative” to go for Sanders or other liberal candidates, said Loveday, who also works for a consulting firm.

But as she told stories of Biden taking photos as he held a fundraiser at her family’s Charleston house, and being so distraught when he bowed out in 2016 that her mother sent her flowers, she conceded that it would probably be a dogfight.

“There is no Obama to bring the turnout,” she said.