ATLANTA and COLUMBIA, South Carolina — Sen. Bernie Sanders has working-class cred, Sen. Elizabeth Warren has plans for equal justice, Sen. Cory Booker was raised in an African Methodist Episcopal church, and former HUD Secretary Julian Castro speaks freely about reparations.

But all the 2020 hopefuls are suffering from the same problem when they're courting the black vote: They’re not former Vice President Joe Biden.

Democratic presidential candidates not named Joe Biden are struggling to break through with African-American voters in Georgia and South Carolina, a huge advantage for the current front-runner as he seeks to ultimately secure the party's nomination.

Even as candidates close in on Biden’s lead in other key early primary states, the South has remained a fortress for Biden, largely on the dominance of his appeal to black voters. He consistently holds a roughly 20-point polling lead among African-American voters nationally, and the lead is larger in the critical early-voting state of South Carolina.

That advantage seems to have been affected little by a string of misstatements, and not much either by attacks on how his policy record, specifically the 1994 crime bill that institutionalized mandatory sentences, negatively impacted the black community.

Why? Well, it all boils down to name recognition, familiarity, and the perception of electability.

“Joe is Joe,” said Harold Crawford, chairman of the Aiken County, South Carolina, Democrats. “I mean, yeah, he comes up with gaffes and what have you, but he's been in the business for quite a number of years, and he has quite a bit of respect.”

A built-in advantage

That built-in advantage was obvious to the five Democrats who broke away from Iowa to campaign in Georgia and South Carolina over the weekend. Even with messages tailored for the black community, candidates have found that a majority of African-American voters have been unwilling so far to give them much of a chance to topple Biden as their No. 1 candidate, largely because, well, he’s the No. 1 candidate.

While other candidates talk a big game about eating into his lead, appearances by five candidates at an Atlanta conference for black Christian millennials over the weekend showed how hard it will be.

For instance, Booker had the crowd of hundreds on their feet, hands raised to the heavens as he quoted Scripture and led them in a call and response. But after the events, attendees told VICE News they want a “president, not a preacher” — and voiced skepticism that Americans would elect another black president. And in a private roundtable, Booker was criticized for not doing enough in Congress for vulnerable populations, according to attendees.

Much like the early skepticism for then-Sen. Barack Obama’s candidacy, voters want to see whether a black candidate can prove they can win among white voters in Iowa first.

“I don't think America is going to elect a black male right now. Not after Trump.”

“Once we saw him win Iowa, we were like, ‘Well, I'll be doggoned,’” Dallas-based Rev. Dr. Briana K. Parker said of Obama. “Booker could be a great president; I'm not going to pretend like I don't think he can. But I don't think America is going to elect a black male right now. Not after Trump.”

Conference-goers expressed similar skepticism about Castro’s candidacy, even after he had the crowd clapping as he ticked off a list of criminal justice, gun control, and voting rights policies.

South Bend, Indiana, Mayor Pete Buttigieg, meanwhile, tried to connect with the crowd by talking about his own faith, but when he mentioned he has a husband, audible and sustained murmurs broke out among the religious crowd, a sign that his entreaties to the faith community will continue to be hampered by resistance to an openly gay candidate, attendees said.

Buttigieg, for his part, said he didn't notice the reaction.

“Look, there's a lot of changes going on in our society, and some people are more accustomed to that than others,” Buttigieg told reporters. “But at the end of the day, this is about making sure that we support each other in living well and living full lives. And there are a lot of questions of justice and exclusion where marginalized people need to team up.”

Castro, who on Tuesday became the 10th Democrat to qualify for the September and October debates, told VICE News he'll try to eat into Biden’s share of the black vote by highlighting Biden’s authorship and support of policies that resulted in a high rate of African-American men in prison.

“Just because somebody is the front-runner right now, they can't be comfortable that they're going to be the front-runner two months from now or five months from now,” Castro said. “Ultimately, whether it's in South Carolina or here in Georgia, or wherever, I believe that people are going to have to address the effects of the ‘94 crime bill, and voters are going to take that into account.”

Reparations

Yet California Sen. Kamala Harris’ recent slide in the polls shows the pitfalls of doing that. In addition to suffering from the same stigma of non-electability among black voters as Booker, people said they were turned off by her aggressive attacks on Biden during the first Democratic debates over his record opposing federal intervention in state school busing.

“I thought it was totally inappropriate, because Joe is not the enemy. I mean, his position on busing was not dissimilar to mine,” said Charles Black, a civil rights activist and one of just eight students to attend the only college class Martin Luther King Jr. ever taught.

Warren, meanwhile, underwhelmed conference-goers as she spoke about teaching Sunday school, how her Methodist childhood shaped her life, and how her worldview can be tied to a biblical parable about taking care of the needy.

“It was like Luther Vandross' curl: It didn't quite make it, man. It was almost there,” said Juard Barnes, a pastor and community organizer from Indianapolis. “I felt like, somehow, I didn't connect with her at the level that I thought I would.”

That will change with time, argued Rev. Miniard Culpepper, Warren’s pastor, who traveled from Massachusetts to be with her in South Carolina. He said he expects Warren support among African-Americans to spike within 60 days.

“I would hope that he doesn't believe, or his team doesn't believe, that he's entitled to the black vote.”

“I’m reaching out to the pastors,” he said. “I think the more they hear, the more she touches them, the more it shifts. They're with Biden because that's who they know the best. As they come to know Sen. Warren, they're going to start shifting to Sen. Warren.”

Sanders’ message of a united working class was well received by attendees, but at a break-out, closed-to-the-press roundtable, he struggled to explain his opposition to slave reparations, and came off defensive and dismissive, to the dismay of some in attendance, including Sanders supporter Gary Lee, a pastor from Conway, South Carolina.

“My candidate hurt [his chances], but I'm a Bernie fan,” Lee said. “It just took a hit.”

Still, Rev. Leah Daughtry, who moderated the discussions with candidates at the Atlanta conference, said Biden shouldn't rest easy. He declined an invitation to the conference, after all, and voters in Iowa won’t even make a choice for about six months.

“The real question is, is the vice president able to maintain that? Because I don't think, and at least I would hope that he doesn't believe, or his team doesn't believe, that he's entitled to the black vote,” she said. “He's got to earn it like everybody else.”