But his advantage has gradually eroded. In a state where African Americans cast 61 percent of the primary vote in 2016, a February Quinnipiac poll showed Biden's support among African-Americans at 27 percent — a 22-point slip from before the Iowa caucus. While almost no one is willing to predict a Biden defeat here, many point to worrisome signs about the state of his campaign.

During a get-out-the-vote effort Thursday in a North Charleston neighborhood just blocks away from Biden’s offices, members of the media rivaled the number of volunteers present. Some prominent black state leaders expected to be firmly in Biden’s camp have migrated to other campaigns, namely those of Tom Steyer and Bernie Sanders.

Dahli Myers, vice chair of the Richland County Council and a former Biden supporter, said she switched allegiances to Sanders after warning several Biden staffers that their grassroots approach was outdated. His get-out-the-vote strategy, she said, was too tailored to older voters and his message of electability too broad to be convincing.

"Before any of these elections took place — the Iowa caucus, or [the] New Hampshire primary, my sense was, there was a structural impediment to people going out and being 'rah rah' and voting for Joe Biden," Myers said. "If the whole of your argument for my vote is, 'I'm electable', and there is nothing that you presented as, you know, the case study for why we should elect you, though you are electable, what is the point? Give me a reason to elect you. And I don't think that that campaign's doing a good job of that."

Some point to Biden’s message as the problem. His "soul of the nation" rhetoric and electability argument, which are rooted in the idea of returning America back to its pre-Trump state, don’t motivate voters, they say. And boasting support from the state's older, prominent black lawmakers, they argue, does not excite the young or infrequent voters needed to build a winning coalition in November.

Rep. Ivory Thigpen, a Sanders endorser who represents Richland County, said his support of Sanders was a “political calculation.” He argued that the electability argument shifts more in Sanders’ favor due to his popularity among young voters, a group Thigpen believes is key to a Democratic win in November.

“I don’t have anything against Biden, I just think he’s a return to the status quo,” he said.

Sanders, who trails Biden in second place according to the RealClearPolitics polling average, has retained much of his South Carolina operation since losing the state to Hillary Clinton almost 3-to-1 in 2016. But it is Steyer, the free-spending billionaire candidate, who has really complicated Biden’s efforts.

While the former vice president has relied heavily on out-of-state surrogates and staffers to bolster his already high profile here, Steyer’s 93-person staff — the largest state campaign operation — comprises almost entirely native South Carolinians.

Steyer has blanketed the state in $15 million worth of broadcast ads and mail pieces since July, while Biden’s first TV ads didn’t begin running in South Carolina markets until early February. Steyer’s wife Kat Taylor, who has been a surrogate for his campaign, moved to Columbia this month to fully support Steyer’s efforts.

In the latest show of Steyer’s muscle, Rep. Gilda Cobb-Hunter, one of the most influential black legislators in the state, joined his campaign as an adviser on Wednesday. Prior to that, she had never supported a presidential candidate during the primary in her 29 years of lawmaking in South Carolina.

“The vice president is a fine man, I have no issues with him. But I am not convinced that Joe Biden can beat Donald Trump,” said Cobb-Hunter, who alluded to Biden’s built-in black support in South Carolina as a fallacy. “Where Steyer has stepped up and Biden has not is simply coming into the state and asking people for their support and going throughout the state, meeting with people and hearing their concerns and responding to the questions that have been posed. The first part of any political victory has to be you’ve gotta show up.”

Cobb-Hunter is one of a number of black South Carolinians who contend that the Biden campaign has relied on its black support to a fault. His high name recognition, they argue, has lulled his campaign into complacency while Steyer and Sanders have vigorously courted African American voters.

Several black lawmakers who supported other candidates said they did so mostly because those campaigns made an effort to reach out to them. The Biden campaign, they said, appeared to have expected their endorsements.

“Joe Biden, in my opinion, believes that he has the African-American vote,” said John King, a state representative who endorsed Steyer on Monday. “He has not spent time in South Carolina and [Steyer’s] people are on the ground.”

“I think some people feel like because he had such a wide lead at the beginning and we have such a long history with him that maybe there was some sort of taking for granted that the support would remain,” said Tameika Isaac-Devine, a Columbia city councilwoman who is still neutral in the race. She has hosted events for 10 contenders in her home, but Biden was not one of them. Steyer, she said, is on her shortlist.

“I think the narrative that African-Americans are following behind one specific candidate is not fair to intellect of African-American voters,” said Rep. J.A. Moore, who endorsed Pete Buttigieg on Wednesday, despite being courted by the Biden campaign. He noted that the former Indiana mayor’s wins in Iowa were in more diverse precincts than those that went to Biden.

“I haven’t seen a real investment of both money and people, and I haven’t seen the vice president spend much time here,” Moore said. “The narrative this election cycle is not taking African-Americans, especially African-American women, for granted. Yet the former vice president hasn’t spent money here nor had an organizational structure here. At least I haven’t seen it.”

Symone Sanders, a senior adviser to Biden who has spent months in and around South Carolina representing him, said the former vice president’s support in the state remains strong due to his decades of relationship-building here.

“I vehemently disagree that his black support has softened. I don’t think his support is soft at all,” Sanders said. “It’s evident in his endorsements that we continue to roll out in the state from not just prominent African-American lawmakers but grassroots African-Americans who have organized in South Carolina for years. We believe that the path to the nomination definitely has to go through South Carolina and we feel good about our organization here.”

When Biden arrived in Columbia Tuesday night for his South Carolina launch party, that energy was evident: at its peak, the predominantly black crowd was standing room only. Attendees took pictures in front of a backdrop decorated with Biden paraphernalia and were given “South Carolina works for Joe” t-shirts. A gospel choir opened the event, which was also attended by a handful of black legislators, many of whom have already endorsed the former vice president.

His most ardent supporters said they were waiting to finally hear from “Uncle Joe” now that Iowa and New Hampshire are behind him.

“The county of Sumter, South Carolina, has more African-Americans than the entire state of New Hampshire,” said state Sen. Marlon Kimpson, who endorsed Biden in January. “Yes, we would rather have done better, but there’s precedent for candidates not winning New Hampshire and Iowa but going on to win the presidency.”

“Joe Biden is the only person who's gonna speak his mind and make sense when confronting a bully like Trump," said Joseph Brown, a Columbia bail bondsman who has been supporting Biden since he first announced his candidacy in April. "That person relates more to a lot of people on the street. And you want the people on the street to come out and vote.”

Biden’s South Carolina campaign representatives say their plan to continue to recruit volunteers, knock on doors, make phone calls and host events to shore up Biden’s support. In addition, according to the campaign, dozens of surrogates and staffers from other Biden state operations will be deployed here in the run-up to the Feb. 29 primary.

"I think the vice president needs to say to South Carolina, 'we're different from those other two primaries'. South Carolina needs someone who has been there and done that and knows how get some things done," said Carl Anderson, a state representative and Biden endorser. "We're gonna prop him up."