Buttigieg and Biden continue to spar ahead of New Hampshire primary

The gloves are off between moderate Democrats looking for a strong finish in New Hampshire.

Former South Bend, Indiana, Mayor Pete Buttigieg -- fresh off a strong showing in Iowa -- and former Vice President Joe Biden -- looking to stave off another loss -- ramped up their attacks against each other ahead of Tuesday's first-in-the-nation primary.

Biden told ABC News Chief Anchor George Stephanopoulos, "I'm saying he hasn't been able to unify the black community -- that's what I'm saying," while highlighting his endorsements from several South Bend black legislators.

"I'm not Barack Obama and neither is he," Buttigieg said in response on ABC's "This Week" Sunday. "Neither is anyone running for president right now -- and this isn't 2008."

"This election is about where our county's headed next and of course how to defeat Donald Trump," he added.

"What I'm offering right now, and the reason I think we have been able to succeed so far, is a message that is about building the sense of belonging and pulling together a coalition, a majority, that will not only defeat Donald Trump, but do it by a big enough margin that we send 'Trumpism' into the history books," Buttigieg said.

African American voters are critical to gaining traction, with the largely Democratic voting base is expected to compose of 12.5% of the electorate in 2020, according to Pew Research Center. In South Carolina, the first primary state in the South, blacks make up nearly 30% of the population.

Buttigieg, just weeks before the South Carolina primary, was asked about his difficulties polling with African-American voters. He told Stephanopoulos that he had to earn black voters.

"Now, I know especially heading into the South that I'm now getting a second look from a lot of voters who, frankly weren't sure if we were competitive in the first place, but know how important it is that we are prepared to build a campaign that calls everybody in -- that will defeat Donald Trump. And that's exactly the work that we're doing," he said. "This is about belonging, both within our campaign and across our country."

The Biden campaign released a video on Twitter taking jabs at Buttigieg's mayoral career. The ad highlighted the demotion and firing of South Bend's police Chief Darryl Boykins and South Bend's fire Chief Howard Buchanon, who are both are African American.

Buttigieg has maintained that he demoted the city's police chief to the rank of captain, because of the chief's failure to inform him that the department was under federal investigation amid reports that Boykins allegedly had ordered people to secretly record racist comments by senior white police officers.

Buchanon, the city's fire chief for five years, had originally submitted retirement papers in 2010, but after Buttigieg's election informed him that he no longer wanted to retire. By that point Buttigieg had already named a replacement for Buchanon, who eventually retired in 2012.

"At this moment, the American people are crying out for something completely different from this classic Washington style of politics. While Washington politics trivializes what goes on in communities like South Bend," Buttigieg's national press secretary, Chris Meagher, said in a statement. "South Bend residents who now have better jobs, rising income, and new life in their city don't think their lives are a Washington politician's punchline. Pete's on the ground experience as mayor, turning around a Midwestern industrial city, is exactly why he is running for president. The Vice President's decision to run this ad speaks more to where he currently stands in this race than it does about Pete's perspective as a mayor and veteran."

Buttigieg was asked during the debate about his record of African American arrests for marijuana possession in South Bend. The former mayor said that he is not afraid to own up to his record.

"Well, I've never been afraid to talk about the good, the bad, and the indifferent that we've experienced in South Bend. But when you were mayor, you're not just calling for good things to happen. You have to be on the ground, figuring it out," he said. "And when it comes to things like the systematic disparity in arrest rates and incarceration rates, when it comes to marijuana South Bend has not been a view."

He added, "I was quick to point out, black residents in South Bend had a lower arrest rate for drug charges than in the state or than in the country but didn't go up over the years. There were ups and downs in the arrest rates and we own that because that's part of the story of our city. It's also part of the story of a country that must legalize marijuana and end these kinds of disparities once and for all. We made tremendous Work progress in the city of South Bend. But of course, we didn't resolve all of these issues. And what we've got to do now is have a national effort and be ready to use the powers of the presidency to reverse the harms of the incarceration policies that I have seen traumatize a generation of kids with incarcerated."

When asked on Sunday how he planned on fixing the problem, Buttigieg told Stephanopoulos, "We need to have a systemic vision for dismantling systemic racism, put it forward. It's called the Douglass Plan. And it's not only about criminal justice reform, taking federal action to lead the way in decarceration. This country, but actually it begins with economic empowerment, making sure that we are supporting black owned businesses, making sure that you know not everybody's going to go start a business."

ABC News' John Verhovek and Molly Nagle contributed to this report.