CONWAY, S.C. — Joe Biden wasn’t going anywhere. Forty minutes. Sixty minutes. Ninety minutes into speaking at a small college here, 30 minutes from Myrtle Beach, he was still talking to the crowd about civil rights, women’s rights, climate change, and free community college.

Once he did wrap up Thursday, the former vice president stayed another hour to greet every lingering person with an outstretched iPhone.

In Biden’s final critical moments before Saturday’s South Carolina primary, he’s pulling in every handshake and seizing on every potentially compelling story from his vast arsenal of anecdotes. All to produce the kind of voter turnout that wins him the state decisively enough to quiet skeptics of his struggling campaign.

Biden, who was polling atop the Democratic presidential race before even declaring his candidacy, has dropped in the last two months, finishing fourth in Iowa and fifth in New Hampshire, and then rebounding slightly with a second-place finish in Nevada. He’s increasingly framed South Carolina, and the African American support he has here, as where his campaign really starts.

Whether he calls it a firewall or not, Biden needs South Carolina to deliver the way he has predicted it will. The Scranton, Pa., native has boasted the support of swing-state Pennsylvania’s Democratic establishment since entering the race, but even that could begin to crack with a loss.

“Make no mistake, I’ve said from the very beginning, this is Ground Zero, the center of political gravity, and Joe Biden has to do well here," said Antjuan Seawright, a Democratic strategist based in South Carolina. “And this is South Carolina — if he does well enough, it will send a message ... to launch into Super Tuesday.”

Biden has a long-standing relationship with South Carolina. A state representative who introduced him Friday morning in Sumter noted that Biden eulogized the last two congressmen from South Carolina to die — one a Republican, one a Democrat. Polling shows Biden leading by as little as 4 and as many as 16 points, ahead of Vermont Sen. Bernie Sanders and billionaire Tom Steyer, who has poured tremendous resources into the state.

At Coastal Carolina University on Thursday night, the campaign said it reached capacity and had to turn people away. Biden’s supporters came ready to rally for him.

“South Carolina, we need you to take back the 2020 election race,” actress Vivica A. Fox implored while introducing Biden.

In Sumter on Friday, State Sen. Thomas McElveen called Biden “the only candidate" to reflect South Carolina’s values: “Vice President Biden’s always been good to South Carolina and tomorrow ... voters in this state will prove to the rest of the Democratic field that South Carolina is Biden Country.”

And Biden on Friday took a moment to express appreciation for, and to remind the crowd of, influential Rep. Jim Clyburn’s endorsement.

Biden has racked up an impressive number of elected officials’ endorsements, but he’s done that in states he lost, too.

Brandon Brown, a former state representative who backs Biden, said that support may be more meaningful here.

“There were a lot of people sitting on the fence waiting for that breakout moment," Brown said. “A lot of African American ministers who have faith and trust in local elected officials often look to the leadership to say, ‘Where should we be going, where should we be looking and directing folks?

» READ MORE: Democratic presidential candidates pictured campaigning for South Carolina primary voters.

Momentum from South Carolina is key to propelling Biden into Super Tuesday. Just three days after the primary here, 14 states will vote on Tuesday, in contests that will award one-third of the total delegates toward the nomination. It’s virtually impossible to scale up a campaign in so many states so fast, especially for a campaign that has been low on money.

Biden has announced campaign stops in California, Texas, and Virginia after the primary here.

“Once he wins South Carolina, the money will start flowing in," said Fletcher Smith, a former state representative consulting for the Biden campaign in the state. “Because people will see he’s the best left-of-center moderate candidate to defeat President Trump in 2020.

Biden drew frequent contrasts with Sanders, who has overtaken Biden as the party’s front-runner, in his final appearances in the state. He said the country “isn’t looking for a revolution ... They’re looking for progress, looking for results.”

Biden made several appeals to black voters, who make up 60% of South Carolina’s Democratic primary electorate, touting his plan to make a $70 billion investment in Historically Black Colleges and Universities and to appoint the first black woman to the Supreme Court. Asked by an audience member how he’d do that with a Republican Senate, he again subtly warned voters against Sanders, who Democrats are warning could cost the party seats in swing districts.

“We need to win back the Senate,” Biden said. "Do you think anyone but me can actually help elect Democratic senators in North Carolina? In Georgia? "

Biden’s most fervent supporters are feeling pressure to deliver.

Paula Myers, a retired teacher, said she’s “never wavered, never will,” when it comes to Biden. She gets frustrated with voters who don’t see his appeal. “If it was a blind resumé test, who would be qualified for this job as president?" she said. "He’s the only one.”

“I will be first in line to vote on Saturday, no question," said Helen Horne, a retired human resources director from Myrtle Beach. “I love him. I think people are sort of blinded by what Bernie is promising.... It’s just not feasible.”

But enthusiasm for Sanders was palpable even in Biden’s must-win state. Sanders held a rally attended by hundreds in Finlay Park in Columbia on Friday afternoon.

And Biden couldn’t escape Sanders fever at his own Sumter rally. Marybeth Berry, a college professor from Columbia, said she sees Sanders’ passion, and as an undecided voter wanted to know what motivates Biden.

He told a story about his father getting — and then quitting — a job at an auto dealership in Scranton after the owner debased staff at a Christmas party by throwing silver dollars on the dance floor to watch employees scramble for them.

“Dignity, that’s what motivates me,” Biden said, appearing a little choked up. "My dad used to say everybody’s entitled to be treated with dignity.” It was a poignant moment for a Biden rally; they often feel long and unfocused.

Berry told reporters she appreciated the answer. “It was very, very good because it was powerful," she said. “To see that fire, to see that passion, to see that integrity matters."

She’s still deciding whom to vote for Saturday.