Frontrunner Joe Biden accused President Donald Trump of putting the United States in a "horrible situation" by overseeing a sharp rise in income inequality during his first presidential primary debate.
Frontrunner Joe Biden came under withering criticism on Thursday from his Democratic rivals for the 2020 presidential nomination, including calls to leave the fight against Donald Trump to a younger generation.
In a sometimes feisty battle of the Democratic heavyweights, the gloves swiftly came off as all candidates attacked Mr Trump in the party's second straight night of debates aimed at introducing candidates to a national audience in the early stage of the battle for 2020.
Former vice president Mr Biden blasted Mr Trump for his "horrible" policies that have exacerbated income inequality, while his chief rival for the nomination, Senator Bernie Sanders, took it directly to the "phoney" president, calling him "a pathological liar and a racist."
But the 76-year-old Mr Biden, back on the debate stage for the first time in seven years, faced an unexpectedly sharp and early attack from a lower-tier candidate half his age, 38-year-old congressman Eric Swalwell, who called on the former vice president to "pass the torch" to a new generation of party leaders.
"I'm still holding on to that torch," Mr Biden snapped back.
Others who confronted the frontrunner included Senator Kamala Harris, the only black woman in the race, who made a stirring call for Biden to recognise his recent "hurtful" comments about being civil with avowedly segregationist US senators.
Mr Biden, with the room dead quiet, insisted he does not "praise racists," and denied that he opposed initiatives in the 1970s to bus children from predominantly black communities to better schools in more prosperous neighbourhoods.
"There was a little girl in California who was part of the second class to integrate her public schools and she was bussed to school every day," Ms Harris said, in one of the most potent moments of the evening.
"That little girl was me."
Mr Biden jousted with nine rivals - each chasing his cherished pole position in the race - on the climactic second night of a sprawling debate featuring Democrats eager to introduce themselves to a national audience.
With so many potential challengers to Mr Trump, the party needed to split the top 20 candidates into debates on two nights in southern Florida, which is expected to be a key swing state in next year's election.
Thursday's session featured four of the race's top five candidates in national polling, including Mr Biden's main challenger Sanders, the 77-year-old US senator whose high-spending policies like universal healthcare have pushed the party leftward in recent years.
The top tier also includes Ms Harris, the only African American woman in the race, and Pete Buttigieg, the gay mayor of South Bend, Indiana who shot to prominence earlier this year but has seen that momentum plateau.
All candidates savaged Mr Trump for his immigration policy, including Senator Kirsten Gillibrand who said the president had "torn apart our moral fabric" by separating children.
Author Marianne Williamson, a surprise presidential candidate who had largely remained sidelined on the stage, offered a more scathing rebuke, likening the policies to "kidnapping" and "child abuse."
"These are state-sponsored crimes," she said.
Mr Biden and other candidates quickly turned against Mr Trump on taxes, health care and income inequality, while early debate also addressed whether the party grounded in capitalism should embrace a shift towards more liberal politics and government involvement in the economy on issues like health care an climate change.
Mr Buttigieg pushed back on extravagant spending promises on health and education, including proposals for a tuition-free public college.
"The children of the wealthiest Americans can pay a little tuition," Mr Buttigieg said. "While I want costs to go down, I don't think we can buy down every last penny for them."
Third place Elizabeth Warren, the rising star progressive US senator, was on Wednesday stage, where she called out disparities in wealth and income and pledged to work to improve the lives of struggling working-class families.
Mr Sanders, a democratic socialist, covered the same ground on Thursday, but he also acknowledged that, in a shift to his Medicare for All platform, Americans would have to pay more taxes.
Mr Biden is the clear leader with 32 per cent support in polling, compared to Ms Sanders at 17 per cent, Ms Harris with seven, and Mr Buttigieg at 6.6.
But while several Democrats have been barnstorming early voting states like Iowa, Mr Biden has eased into campaigning since he launched his candidacy on 25 April, largely avoiding confrontation with rivals.
That changed on Thursday, with Mr Biden in the hot seat.