Democratic presidential contenders Bernie Sanders and Pete Buttigieg, the top finishers in , faced a barrage of criticism on Friday from rivals who said they did not have what it takes to beat Republican Donald Trump in November.
In a heated debate in New Hampshire just four days before the state's pivotal primary, their Democratic rivals questioned whether Senator Sanders' democratic socialist views and Mr Buttigieg's relative lack of experience and lack of support with African-Americans and Latinos made them too much of a risk for the 3 November election.
Senator Sanders, 78, a US senator and leader of the party's progressive wing, and Mr Buttigieg, the 38-year-old former mayor of South Bend, Indiana, finished in a virtual dead heat in Iowa's first-in-the-nation caucuses earlier this week.
Former Vice President Joe Biden, the one-time national front-runner who finished a disappointing fourth in Iowa, delivered his most aggressive performance yet, a sign of determination as he looks to rebound.
Mr Biden said Mr Trump would have an easy time ripping into Senator Sanders in a general election campaign, and Senator Sanders would drag down other Democratic candidates in federal and state races.
"Bernie has labelled himself, not me, a democratic socialist. I think that’s the label that the president is going to lay on everyone running with Bernie if he is the nominee," Mr Biden said.
US Senator Amy Klobuchar, who finished a distant fifth in Iowa, said Senator Sanders would not attract the kind of centrist voters Democrats need to win.
"Donald Trump’s worst nightmare is a candidate who will bring people in from the middle," Senator Klobuchar said at the eighth Democratic debate. "I think we need someone to head up this ticket that actually brings people with her instead of shutting them out."
Senator Sanders, who has called for a political revolution that will attract new voters, said "the way to beat Mr Trump is by having the largest voter turnout in the history of this country."
US Democratic presidential hopefuls faced off in a debate in New Hampshire four days before the state's pivotal primary, Source: AP
He said he could appeal to working class voters who have given up on the political process.
Mr Biden and Senator Klobuchar also questioned whether Buttigieg had enough experience to face off with Trump.
Mr Buttigieg, who served two terms as mayor of South Bend, a city with a population of 100,000, said the Washington insider experience of some of his rivals was no longer what was needed, and it was time to "turn the page" on the old Washington politics.
"It is easy to go after Washington, because that’s a popular thing to do," Senator Klobuchar said, telling Mr Buttigieg that "it’s popular to say and makes you look like a cool newcomer."
Historically, candidates who win the Iowa caucuses see a boost in New Hampshire, and two opinion polls released this week showed Mr Buttigieg within striking distance of Senator Sanders, who has consistently been atop the field in the state.
Vermont Senator Bernie Sanders, former US Vice President Joe Biden and Massachusetts Senator Elizabeth Warrren Source: AP
Mr Biden did not seem confident about how he would do.
"This is a long race. I took a hit in Iowa, and I’ll probably take a hit here," he said.
With controversy surrounding the Iowa caucuses - technical problems and inconsistencies delayed the results for days - New Hampshire's primary on Tuesday takes on added importance.
Billionaire Tom Steyer, who has focused heavily on upcoming primaries in the more diverse states of Nevada and South Carolina, launched a lengthy discussion of race and noted the party's broad diversity - and the mostly white candidates on the stage aside from Andrew Yang, an Asian-American.
He took a swipe at Mr Buttigieg, saying he has not been able to show much appeal to the black and Latino voters who are crucial to a winning Democratic campaign.
"Unless you can appeal to the diverse parts of the Democratic Party, including specifically the black community, including specifically Latinos, if you can’t do that, then we can’t beat Donald Trump in November," Mr Steyer said.
Mr Buttigieg came under fire for his record on race in South Bend.
When asked about an increase in arrests of blacks on marijuana-related charges, he said as mayor he targeted cases "when there was gun violence and gang violence."
