Elizabeth Warren ends presidential bid, leaving Biden, Sanders to fight for Democratic voters

Warren, a liberal senator who won plaudits for her command of policy details, finished well behind the two front-runners on Tuesday in 14 states, including her home state of Massachusetts, leaving her path to the nomination virtually nonexistent.

Her exit makes the contest a two-man race between moderate former Vice President Joe Biden and liberal U.S. Senator Bernie Sanders, who in many ways represent the main wings of the Democratic Party. Warren's departure leaves what had once been the most diverse field of candidates in U.S. history as a contest primarily between two white men with decades in office each nearing 80 years old.

It was not clear whether Warren, who still commands a loyal base of supporters, would endorse either of her rivals.

Her relationship with Sanders may have been strained in January, when she accused him of calling her a liar on national television after he denied telling her in 2018 that a woman could not beat Republican President Donald Trump.

In a conference call with her campaign staff, Warren said, "Never again can anyone say that the only way that a newcomer can get a chance to be a plausible candidate is to take money from corporate executives and billionaires."

Warren swore off big donors when she launched her run and raised more than $112 million from grassroots contributions.

She vowed to continue fighting for ordinary Americans and touted the impact the campaign has already had, bringing attention to ideas such as a wealth tax and proving that candidates do not need high-dollar fund-raisers to succeed.

'VICIOUS CYCLE' ON ELECTABILITY

The vague notion of "electability," a frequent buzzword on the campaign trail as Democrats prioritised defeating Trump over all other concerns, seemed to hurt Warren and non-white male candidates.

"The general narrative was that the women might be too risky, and I think there were people who heard that enough that it started showing up in polling ... and becomes a vicious cycle that was hard to break out of," said Christina Reynolds, vice president of communications at EMILY's List, which works to elect women favouring abortion rights and had endorsed Warren.

U.S. Representative Tulsi Gabbard remains in the race, but has repeatedly failed to win even 1% of the vote in primaries.

Meanwhile, Biden and Sanders continued to step up attacks on each other following Biden's unexpectedly strong performance on Super Tuesday earlier this week.

The back-and-forth between the two contenders signalled a bruising battle to come as the race turns next to six states stretching from Mississippi to Washington state, which vote on March 10.

Sanders blamed the "establishment" and corporate interests for his losses in 10 of the 14 states that voted on Tuesday, a charge Biden called "ridiculous."

"You got beaten by overwhelming support I have from the African-American community, Bernie," Biden told NBC's "Today" show on Thursday. "You got beaten because of suburban women, Bernie. You got beaten because of the middle-class, hardworking folks out there, Bernie."

Biden received more support from black voters and women, particularly in suburban areas, exit polls found. Those two groups make up a substantial part of the Democratic electorate and were credited with delivering the party big wins during the 2018 midterm congressional elections.

Biden also pointed out that Sanders has raised more campaign cash, responding to criticism that his moderate rival is collecting money from corporate interests. Aside from candidates who have self-funded their campaigns, Sanders has boasted the largest cash hauls during this election. At the end of January, Sanders had raised $134 million while Biden raised $70 million.

Like Warren, Sanders has refused to hold fundraisers and instead relies on online donations. Biden, who has seen his online giving spike in recent days, regularly holds high-dollar fundraising events.

In addition to Mississippi and Washington state, voters in Michigan, Missouri, and Idaho on Tuesday. North Dakota will hold caucuses.