SUMTER, S.C. — Joe Biden on Saturday offered a sweeping defense of his decades-long public record after weeks of direct criticism from his Democratic rivals, while also expressing regret for the first time for recent comments highlighting work with segregationists in the Senate.

In remarks to a heavily African American audience here, Biden at times offered an apology, an explanation or in some cases a determined defense for past policy positions and comments, primarily on issues of race but also bankruptcy legislation and the 2002 Iraq war authorization. Acknowledging the increased willingness of his rivals to target his record, Biden responded with what he presented as the ultimate validation of his career: Barack Obama’s selection of him as his vice president.

"I will take his judgment of my record, my character, and my ability to handle the job over anyone else’s,” Biden said to applause.

Biden told the audience that he first entered public service motivated by the civil rights movement and a desire to shift the Democratic Party in a more progressive direction. He then took that fight into the Senate, he said, where he had no choice but to work alongside individuals whose views he found “repugnant” and “offensive.” He fought those lawmakers on civil rights “and won,” he said.

But then he acknowledged the “misstep” weeks ago at a Democratic fundraiser when he noted he had to work alongside segregationists when he first joined the Senate, but did so with “civility.”

“Now was I wrong a few weeks ago, to somehow give the impression to people that I was praising those men who I successfully opposed, time and again? Yes, I was,” he said. "I regret it and I am sorry for any of the pain or misconception that may have caused anybody.”

"But, should that misstep define 50 years of my record for fighting for civil rights and racial justice in this country? I hope not. I don't think so,” he added. "That just isn't an honest assessment of my record. I'm going to let my record and my character stand for itself and not be distorted or smeared.”

The former vice president was already on the defensive for his segregationists' comments when Sen. Kamala Harris of California seized on them in the first Democratic presidential debate to ask Biden why he had joined some of those same lawmakers to fight against busing as a means to integrate segregated school systems.

The ensuing back-and-forth has shadowed Biden, particularly this week as both he and Harris campaigned in Iowa. The choice now of South Carolina as the place to try and put the issue to rest — and to do so by invoking Obama’s name so explicitly — was notable in a state where African American voters will likely make up a majority of the voters in next February’s first-in-the-South primary.

A CBS News-YouGov poll of South Carolina voters conducted in mid-June showed that Biden’s service as Obama’s vice president was the number one reason why voters said they were considering him in the primary. Biden led the field in that survey with 45 percent.

Ian Sams, national press secretary for the Harris campaign, offered a preemptive rebuttal of Biden’s remarks on Twitter.

“Every candidate's record will (and should) be scrutinized in this race. It's a competition to become President of the United States. There are no free passes,” he wrote.

Every candidate's record will (and should) be scrutinized in this race. It's a competition to become President of the United States. There are no free passes. — Ian Sams (@IanSams) July 6, 2019

But Biden went beyond his record on race. He said he was not “beholden to big banks,” referring to his support for a bankruptcy bill more than a decade ago. He saw legislation that was en route to passage and fought to improve it, he said, adding that no one could doubt his advocacy for the middle class.

And he noted his vote to give President George W. Bush authorization for the war in Iraq, but highlighted his work in the Obama administration to bring U.S. forces home, “including my son.”

The infighting among Democrats – especially directed at him – was counterproductive, Biden suggested, when the focus should be on defeating President Trump.

"Many who want this campaign to be about my past. I get it. That’s the game. But this isn’t a game. Everyone of you, no matter who you’re for, know in your bones that this election is different,” he said.

Biden has not been shy about highlighting his connection to Obama throughout his campaign so far, often referring to him in speeches as his “buddy” and highlighting their partnership in some of the administration’s biggest policy fights, especially the Affordable Care Act.

Days after announcing his candidacy, Biden’s campaign released a video that included Obama’s effusive praise for Biden as he awarded him the Presidential Medal of Freedom in the final days of his White House tenure.

Obama has not endorsed Biden in the primary, though a spokesperson issued a statement praising him when he entered the race — something they had not done for any other candidate. The statement also made clear Obama’s preference not to put his thumb on the scale in the primary.