WASHINGTON — Barack Obama has not set foot in South Carolina recently, but he has become a flash point among the Democratic presidential candidates as they compete for black voters in Saturday’s primary there and in the bigger, diverse Super Tuesday contests next week.
In statements and a campaign ad over the past few days, former Vice President Joseph R. Biden Jr. has accused Senator Bernie Sanders of disloyalty against the nation’s first black president for considering a primary challenge against Mr. Obama in 2012. Mr. Sanders insists he didn’t consider it.
Former Mayor Michael R. Bloomberg has spent about $22.4 million so far on two national television ads featuring several photos of him with Mr. Obama, something Mr. Biden has sought to undercut by questioning whether the two men were close.
Other candidates have praised Mr. Obama on the airwaves and debate stages as well as in early primary and caucus states this month, a sharp turnaround from the criticism that some 2020 contenders lobbed last year at his record, especially on immigration. The new embrace is a measure of his popularity with black voters 12 years after his last contested election in South Carolina, where he beat Hillary Clinton in a rout that cemented, once and for all, his standing with black voters nationwide.
Mr. Obama hasn’t tried to referee how the current candidates are using his name, image or record, and he has studiously avoided playing favorites. He does have opinions about the race, several of his allies say, but has made it clear that he sees his main role as unifying the party after a nominee is selected and helping ease tensions among warring supporters.
As Mr. Sanders’s campaign gained steam a few weeks ago, Mr. Obama said he would enthusiastically support any of the candidates. But he added that the task of uniting the party around Mr. Sanders “could be difficult,” according to an associate who spoke on condition of anonymity to describe a private conversation.
Mr. Obama has imposed no restrictions on Democratic candidates who want to hug him for political gain, regardless of their history or ideological orientation. Five Democratic candidates — Mr. Bloomberg, Mr. Sanders, Mr. Biden, Tom Steyer and Senator Elizabeth Warren — have seized on the opportunity, using Mr. Obama’s words or likeness in their ads. And just about everybody, surrogates and other candidates alike, have invoked him on the stump.
“I think it would be political malpractice for any of the candidates not to closely associate themselves with the most popular person in the Democratic Party,” Valerie Jarrett, one of Mr. Obama’s closest friends and advisers, said in an interview. “South Carolina was one of the biggest and most important days of our campaign. People will always remember that.”
It is not just Democrats citing Mr. Obama. A pro-Trump super PAC aired a deceptive TV ad earlier this week manipulating a 1995 Obama audiobook to make it appear that Mr. Obama was accusing Mr. Biden of betraying black voters. On Wednesday, Mr. Obama’s lawyer sent a cease-and-desist letter to the group’s executive director after Mr. Biden’s campaign alerted him to the problem.
Mr. Obama, who offered Mr. Biden’s team basic strategic advice before he entered the race last year, speaks more often with his former vice president than with other candidates, and called to buck up Mr. Biden after his humbling loss in the Iowa caucuses, according to a person briefed on the exchange. The two men also spoke on Tuesday ahead of the South Carolina debate, The Times reported.
In South Carolina, Mr. Biden has intensified his Joe-hearts-Barack strategy, weaponizing the president’s popularity as a battering ram to punish Mr. Sanders and Mr. Bloomberg for making Mr. Obama sweat for their support in 2012.
In a recently unearthed audio recording of a 2016 speech, Mr. Bloomberg claimed to have given Mr. Obama a “backhanded” endorsement. Mr. Sanders, a Vermont independent who clashed with the administration on health care and other issues, referred to Mr. Obama in a 2011 radio appearance as a “disappointment,” and, according to a recent article in The Atlantic, even flirted with a primary challenge before being talked out of the idea by his friend Harry Reid, the former Democratic leader of the Senate.
“He wanted a primary. He said we should primary Barack Obama, someone should, and, in fact, the president was weak and our administration was in fact not up to it,” Mr. Biden said during Tuesday’s contentious Democratic debate in Charleston, shortly after cutting an online ad calling out Mr. Sanders for his actions eight years ago.
Representative Cedric Richmond, Democrat of Louisiana, a Biden backer and a recent chairman of the Congressional Black Caucus, said that Mr. Obama was “still very, very significant for African-American voters,” and that other candidates were misrepresenting history as they try to win over black Democrats.
Mr. Richmond added that it was “hypocrisy” for Mr. Bloomberg and Mr. Sanders to run ads saying they were “BFFs” with Mr. Obama “after refusing to help out Obama when he needed them.”
A Biden adviser, speaking on condition of anonymity to discuss campaign strategy, said the campaign’s view was that the attacks on Mr. Sanders over Mr. Obama were less likely to have an impact than the campaign’s criticism of Mr. Bloomberg, who is not on the ballot in South Carolina. Mr. Sanders, the person said, has locked in many of his supporters, but Mr. Bloomberg, a former Republican who could siphon off moderate support in Super Tuesday states, is more vulnerable to charges of disloyalty.
Mr. Sanders, for his part, has repeatedly said that he views Mr. Obama as a historic “icon” with whom he had policy disagreements, and has insisted he never planned to challenge him.
But aides who worked for Mr. Obama’s re-election campaign said they believed the threat was real and had fueled fears that such a challenge could sap much-needed support from the party’s progressive wing. “He should be held accountable,” Patrick Dillon, a senior adviser to Mr. Obama’s 2012 campaign aide, said of Mr. Sanders. “It was clear he was up to something.”
Mr. Sanders and Mr. Obama, while not close, are on amiable terms, and the senator has called the former president in recent weeks to update him on his campaign, and to keep their lines of communication open, according to aides to both men.
Mr. Obama, in turn, has expressed admiration for Mr. Sanders’s tenacity and small-donor fund-raising operation and his political acumen, but he has also acknowledged the magnitude of the challenge of getting other Democrats to fall into line quickly behind Mr. Sanders if he wins, a person in his orbit said.
Mr. Obama and Mr. Bloomberg also have a complicated history, but their relationship is tempered by their past collaborations. The Bloomberg and Obama teams worked closely on a range of initiatives when both men were in office — especially on gun control and climate change.
The two men spoke briefly after Mr. Bloomberg announced he was running for president in November, with Mr. Obama gingerly questioning his late entry into the race, a person with knowledge of the exchange said.
The former mayor had an open line of communication to Ms. Jarrett, who served as Mr. Obama’s intergovernmental liaison in the White House. That back channel has remained open, and Mr. Bloomberg’s team has taken steps to mitigate any toll that his recent actions and statements might have on their relationship.
Mr. Bloomberg’s campaign manager, Kevin Sheekey, has reached out to members of Mr. Obama’s team, especially Ms. Jarrett, to explain the former mayor’s change of heart on the city’s much-criticized stop-and-frisk policing strategy and his use of nondisclosure agreements at his media company, she said.
The impact of the friction remains an open question, but people around both Mr. Sanders and Mr. Bloomberg say they believe that the threat posed by President Trump will overshadow the squabbling and slights.
“We love Barack Obama, but I’m not sure all of this has as much influence on voters as it might have if we weren’t facing a massive threat from Donald Trump,” said Stephen K. Benjamin, the mayor of Columbia and a Bloomberg supporter. “He’s a symbol of pride, and a reminder of how things were in a better time.”
In reality, many black voters in South Carolina warmed slowly to Mr. Obama, who was still a little-known freshman senator from Illinois when the 2008 race began. One of Mrs. Clinton’s biggest assets heading into the state that year, or so it was assumed at the time, was her husband, former President Bill Clinton, who was widely popular with black voters.
That changed, in part, as Mr. Obama campaigned aggressively in South Carolina in 2007 and 2008 and then won the Iowa caucuses. Mr. Clinton also made a mistake of attacking Mr. Obama in the days leading up to the South Carolina primary, dismissing Mr. Obama’s antiwar position as a “fairy tale” and comparing him to a past black presidential candidate, Jesse Jackson, who lost in 1984 and 1988.
Mr. Obama is dead set on avoiding that kind of mistake, his allies say, and has been unsettled by the vitriol vented at this week’s debate.
“The spirited debate is fine,” Ms. Jarrett said. “But he’d prefer they avoid the low blows, and not bait one another quite so much.”
Nick Corasaniti contributed reporting.