Surging frontrunner Bernie Sanders has come under withering fire in a Democratic debate in South Carolina, as rivals criticised the high cost of his ambitious economic agenda and warned he would cost the party the White House and control of Congress.
In a contentious debate that featured candidates repeatedly shouting over one another in a bid for attention, Mr Sanders' opponents united in attacking the independent senator and self-avowed democratic socialist as a risky choice to lead the party against Republican President Donald Trump in November.
"Bernie will lose to Donald Trump, and Donald Trump and the House and the Senate and some of the statehouses will all go red and then between gerrymandering and appointing judges, for the next 20 or 30 years we are going to live with this catastrophe," billionaire former New York Mayor Michael Bloomberg said.
Pete Buttigieg, the moderate former mayor of South Bend, Indiana, criticised Mr Sanders for the shifting estimates on the costs of his proposals such as government-run health care.
"I can tell you exactly how it all adds up. It adds up to four more years of Donald Trump," Mr Buttigieg said.
"Not only is this a way to get Donald Trump re-elected, we got a House to worry about, we got a Senate to worry about."
Mr Sanders said he was raising issues that "the American people want, by the way ... raising the minimum wage to a living wage, 15 bucks an hour, making public colleges and universities tuition-free."
Mr Sanders has taken command of the race after strong showings in the first three nominating contests in Iowa, New Hampshire and Nevada.
Pete Buttigieg and Bernie Sanders before the start of the New Hampshire Democratic presidential primary debate earlier in February. Source: AP
His momentum has alarmed a Democratic establishment wary that his plans to end economic inequality and strengthen the social safety net will lead to defeat against Mr Trump.
Even Elizabeth Warren, a senator from Massachusetts and progressive ally of Mr Sanders, took a swing at her old friend.
"I think I would make a better president than Bernie. And the reason for that is that getting a progressive agenda enacted is going to be really hard," she said.
"I dug in, I did the work, and then Bernie's team trashed me."
The debate is the third this month and the 10th overall for the Democrats vying for the right to challenge Mr Trump in the 3 November election.
It is their final encounter before Saturday's South Carolina primary and next week's 14 vital Super Tuesday contests.
