Democratic presidential candidates on Sunday touted their electability ahead of upcoming primary contests in Nevada and South Carolina, both of which boast more diverse populations than the overwhelmingly white Iowa and New Hampshire.

Many also cast doubt on former New York City Mayor Michael Bloomberg Michael BloombergTop Democratic super PAC launches Florida ad blitz after Bloomberg donation The Hill's 12:30 Report - Presented by Facebook - Latest with the COVID-19 relief bill negotiations The Memo: 2020 is all about winning Florida MORE's fitness as a candidate as he defends previous remarks in support of stop-and-frisk policing and his use of his substantial personal wealth to propel him in the polls.

Sen. Amy Klobuchar Amy KlobucharThe Hill's Morning Report - Sponsored by The Air Line Pilots Association - White House moves closer to Pelosi on virus relief bill EPA delivers win for ethanol industry angered by waivers to refiners It's time for newspapers to stop endorsing presidential candidates MORE (D-Minn.), coming off of a third-place finish in the New Hampshire primary, conceded she needs to attract more support among African American and Latino voters ahead of the upcoming contests.

“That’s gonna be on me. I need people to get to know me,” Klobuchar told ABC’s Martha Raddatz. “I’ve always gotten high support in all of my elections with the Hispanic and African American communities in my state. That is a start.”

Asked if she was “running out of time” with such voters, Klobuchar responded, “No, because my name identification in states outside of the early few states was not that high simply because I didn’t have the money, unlike Bloomberg, to run more ads during your show than I am on being interviewed during your show.”

Former South Bend, Ind., Mayor Pete Buttigieg Pete ButtigiegBipartisan praise pours in after Ginsburg's death Bogeymen of the far left deserve a place in any Biden administration Overnight Defense: Woodward book causes new firestorm | Book says Trump lashed out at generals, told Woodward about secret weapons system | US withdrawing thousands of troops from Iraq MORE, who, like Klobuchar, has struggled to build momentum with African American and Latino voters, predicted they would be swayed by the argument that he was the most electable because voters prioritize defeating President Trump Donald John TrumpObama calls on Senate not to fill Ginsburg's vacancy until after election Planned Parenthood: 'The fate of our rights' depends on Ginsburg replacement Progressive group to spend M in ad campaign on Supreme Court vacancy MORE.

"We dare not get this wrong, and that means nominating a candidate who can challenge this president on his own terms," Buttigieg said.

Former Vice President Joe Biden Joe BidenSenate Republicans face tough decision on replacing Ginsburg What Senate Republicans have said about election-year Supreme Court vacancies Biden says Ginsburg successor should be picked by candidate who wins on Nov. 3 MORE, meanwhile, said “overwhelming support” from African American voters in South Carolina could help him regain his footing after a disappointing fourth-place finish in Iowa and a fifth-place finish in New Hampshire.

"You can't win — you can't take it for granted. Last time we ran, it was basically taken for granted," Biden said on NBC's "Meet the Press." "I'm the only one who has the record and has the background and has the support. They know me. They know who I am."

The former vice president conceded on NBC’s “Meet the Press” that he needs to “do really well” in South Carolina to set himself up for Super Tuesday, telling host Chuck Todd Charles (Chuck) David ToddSunday shows - Trump team defends coronavirus response Strzok: 'I continue to believe that Donald Trump is compromised by the Russians' GOP chair defends Trump messaging on masks: 'To say that he should have known then what we know now isn't really fair' MORE that on March 4 "we end up going into all the states, which the polling data is now showing me doing incredibly well. Whether it's North Carolina or Georgia or Texas or any of these other places."

South Carolina is considered a must-win state for Biden, who has been banking on his strong support in the African American community, but the interviews come as recent polling indicates Bloomberg is cutting into Biden's lead with African American voters in the state. A Quinnipiac University poll released Monday showed Bloomberg rising to 22 percent among black voters, while Biden’s share of support fell to 27 percent.

Bloomberg, who has appeared in the top five in several polls and blanketed the airwaves with advertising despite not yet being on the ballot in any contests, was confronted last week with a recording released by progressive podcast host Benjamin Dixon in which the former mayor defended the racial disparities in New York’s stop-and-frisk policy.

Biden, who was himself the subject of media scrutiny over his support of “tough on crime” policies in the early 1990s and opposition to federally mandated desegregation busing in the 1970s, suggested the scrutiny that accompanied Bloomberg’s rise in the polls could hinder him among African Americans.

"There's a lot to talk about with Michael Bloomberg," Biden said on "Meet the Press." "You all are going to start focusing on him like you have on me, which I'm not complaining, like you have on me the last six months. You're going to focus on him, his position on issues relating to the African American community, from stop and frisk to the way he talked about [former President Obama]."

Klobuchar, who recently received scrutiny for her record as a prosecutor, lamented that Bloomberg’s wealth enabled him to run ads without needing to promote his candidacy on Sunday shows, where he would likely be questioned about his history on racial issues and allegations of inappropriate remarks to women.

"I think he has to come on a show like yours," Klobuchar said on CNN's "State of the Union." "I don't think you should be able to hide behind airwaves and huge ad buys."

"He has to come on these shows, and I'm also an advocate for him coming on the debate stage. ... I know I'm not going to beat him on the air, but I can beat him on the debate stage because I believe my argument for my candidacy is so much stronger," she added.

Bloomberg’s history has also caught the attention of the White House, with Trump, who has himself frequently spoken in favor of stop and frisk, tweeting that Bloomberg was a “total racist” in a since-deleted tweet.

Fox News’s Chris Wallace Christopher (Chris) WallaceBiden town hall draws 3.3 million viewers for CNN Gates says travel ban made COVID-19 worse in US CNN slammed for soft questions during Biden town hall: 'The media is broken' MORE pressed counselor to the president Kellyanne Conway Kellyanne Elizabeth ConwayGeorge and Kellyanne Conway honor Ginsburg Trump carries on with rally, unaware of Ginsburg's death George Conway hits Trump on 9/11 anniversary: 'The greatest threat to the safety and security of Americans' MORE on the apparent contradiction on “Fox News Sunday,” to which she responded, “The president is toying with everybody by saying, had he said something like that, everyone would say, ‘Racist, racist, racist.’”

In a statement, Bloomberg spokeswoman Sabrina Singh said, "It’s not surprising that as Mike continues to rise in the polls, other candidates, including Donald Trump, start to get nervous. Because they’re seeing Mike winning over voters across this country with his record of taking on tough fights and strong case that he is the only candidate to defeat Trump in November."