President Biden’s campaign and affiliated groups are amping up their efforts in South Carolina, pouring in money and staff ahead of the first Democratic primary in February in an effort to generate excitement for his campaign in the state.

It seems, at first glance, to be a curious political strategy. Few incumbent presidents have invested so much in an early primary state — particularly one like South Carolina, where Mr. Biden faces no serious primary challenger, and where no Democratic presidential candidate has won in a general election since Jimmy Carter in 1976.

But the Biden campaign sees the effort as more than just notching a big win in the state that helped revive his struggling campaign in 2020, putting him on the path to winning the nomination. It hopes to energize Black voters, who are crucial to Mr. Biden’s re-election bid nationally, at a moment when his standing with Black Americans is particularly fraught.

“One of the things that we have not done a good job of doing is showing the successes of this administration,” said Marvin Pendarvis, a state representative from North Charleston. He added that the campaign will need to curate a message “so that Black voters understand that this administration has done some of the most transformational things as it relates to Black communities, to minority communities.”

Four years after Mr. Biden vowed to have the backs of the voters he said helped deliver him the White House, Black Americans in polls and focus groups are expressing frustration with Democrats for what they perceive as a failure to deliver on campaign promises. They also say that they have seen few improvements to their well-being under Mr. Biden’s presidency. Some are unsure whether they will vote at all.

To counter that pessimism and boost Black turnout, Democrats are hitting the Palmetto State with a six-figure cash infusion from the Democratic National Committee, a slew of campaign events and an army of staffers and surrogates.

Party leaders are hoping for a large showing at the polls, which would broadcast to the rest of the country the importance of Black voters and their support for Mr. Biden’s re-election, re-energize a must-win bloc and ignite the momentum that was seen in 2020.

“That’s another part of the historic nature of South Carolina going first,” said Christale Spain, the chairwoman of the South Carolina Democratic Party who was elected in April. “This is the first time that Black voters are going to vote first to choose the president.”

But the scale of Mr. Biden’s investments reflects the challenge he faces. Lackluster turnout by Black voters in February could be more than a stumbling block; it could be a dire sign that Democrats are disconnected from one of their most loyal constituencies.

Increasing Black turnout in South Carolina will be an especially tall order for both the state party and Mr. Biden’s campaign in 2024. Many South Carolina Democrats are still nursing wounds from the 2022 midterm elections, in which the party lost several safe state House seats and Black turnout fell to its lowest point in decades.

“You have people who are discouraged because they have not seen the policies translate into their mailbox, their ZIP code,” said Marlon Kimpson, a longtime Biden ally and former state senator who was appointed to the White House Advisory Committee for Trade Policy and Negotiations this year. “And I attribute that to poor communications, quite frankly, out of Washington, D.C. That is improving.”

Democrats’ efforts in South Carolina over the next several weeks will amount to a one-state test case of Mr. Biden’s appeal to Black voters, and they hope the results can be replicated across the country.

Starting in early January, where Black South Carolinians groan about higher prices and failures on student loan debt relief, they will find Democrats on the airwaves and at their doors praising the Biden administration’s push for rural broadband access and increased funding to Black colleges and universities.

Party leaders in rural counties who might feel neglected by Democrats in more populous areas of the state will be able to greet national party brass in their own communities at stops along a multiweek bus tour, which campaign officials say will crisscross the state and deploy multiple Biden surrogates. Mr. Biden and Vice President Kamala Harris are expected to visit the state at least once ahead of the Feb. 3 primary.

And as alarm grows over the pronounced number of Black voters who say they are considering supporting former President Donald J. Trump or not voting at all in November, allies of Mr. Biden will be underlining Mr. Trump’s rebuke of democratic norms and trying to explain away the criminal justice and economic measures Republicans have elevated to help appeal to some Black voters.

“I think we just have to give a clear message that the alternative is much worse,” said State Representative Ivory Thigpen, chairman of the state’s legislative Black caucus, referring to the possibility of another Trump term. “I know that isn’t the best campaign strategy, but it’s the reality.”

Several local and statewide elected officials have met repeatedly over the last few weeks to workshop messages to disaffected Black voters, with an emphasis on reaching Black men, who have shown more openness to supporting Republicans in November. Black leaders have also held a series of meetings with White House officials aimed at countering disinformation related to Democratic policies and stopping any further fracturing of Democrats’ base of Black voters.

Biden campaign officials did not provide specific turnout figures that they were aiming for. But no one expects a repeat of 2008, when South Carolina’s Black voters, motivated by the prospect of electing America’s first Black president, Barack Obama, turned out en masse. On the question of turnout, some Democrats have already sought to temper expectations.

“In the absence of any meaningful opposition, it’s hard to get people excited to turn out,” said Mr. Kimpson. “I don’t think that translates to lack of enthusiasm for the president at all.”

As the Biden campaign focuses on South Carolina, it has maintained little to no presence in several states that are certain to be more competitive in November. The thin campaign apparatus in Georgia, Wisconsin and Pennsylvania has caused some concern among Democratic organizers, even as the campaign says it will expand its presence in battleground states later next spring.

South Carolina Democrats have also staked their success in February on the chance to host the first primary again in 2028, when the party will have a competitive primary field. And a strong showing in February could lay the groundwork for the party to protect against big losses next November, like those in 2022.

“The fact that we’re doing all of this is because we’re first and we take that status very seriously,” said Ms. Spain. “Our goal is to turn out as many Black voters as possible.”

Reid J. Epstein contributed reporting.