Minnesota Senator Amy Klobuchar will abandon her candidacy for the 2020 Democratic presidential nomination.
Amy Klobuchar. Photo: AFP
Senator Klobuchar came in a distant sixth place in Saturday's South Carolina primary.
Klobuchar will join former Joe Biden at his Dallas rally tonight to endorse the former vice-president, US media report.
The news comes on the heels of fellow moderate Pete Buttigieg suspending his campaign on Sunday.
Despite some strong debate performances and a surprise surge in New Hampshire, Klobuchar's campaign failed to gain major traction.
On the trail, the Minnesota senator sold herself to moderate voters as the candidate who could win swing states back for the Democrats. However, her profile was largely eclipsed by centrist rivals Biden and Buttigieg.
Klobuchar's exit leaves the seven delegates she has won from previous primaries free to vote for another candidate. Bernie Sanders, the leftwing Vermont senator, currently leads the delegate count.
The race now heads to Super Tuesday, when voters in 14 states will go to the polls and present a test for the remaining candidates.
Klobuchar's withdrawal leaves five Democrats in the race for the party's nod to run against Republican Donald Trump in November.
Democrats still in the nomination fight
Bernie Sanders
The US senator from Vermont with an impassioned following is making a second attempt at the presidency and secured a position as front-runner after the first nominating contests.
Sanders won New Hampshire and Nevada, finished a close second in Iowa to Buttigieg and well behind Joe Biden in South Carolina.
As in his first presidential run in 2016, Sanders, 78, has campaigned as an unapologetic, self-described democratic socialist who seeks nothing less than a political revolution.
Sanders, whose signature issue is government-run universal healthcare, has again proven to be a fundraising powerhouse, leading the field in terms of total campaign contributions.
Joe Biden
Biden, who was vice president under President Barack Obama, built his candidacy on the argument that his more than 40 years in elected office makes him best suited to take over from Trump on Day One.
Lacklustre performances in Iowa and New Hampshire cost Biden his front-runner status, though his campaign argued Nevada and South Carolina would be a better test of his ability to assemble a diverse coalition of supporters that includes African Americans, Hispanics and working-class white voters.
Biden finished second in Nevada and a decisive first in South Carolina.
At 77, questions persist about his age and his moderate brand of politics, which progressives contend is out of step with the leftward shift of the party.
Trump's apparent effort to push the Ukrainian government to investigate Biden and his son Hunter, which resulted in Trump's impeachment, appeared to boost Biden's argument that the president views him as a threat.
Michael Bloomberg
Media mogul and former New York City Mayor Bloomberg, 77, announced his candidacy in November, very late in the game.
In an unusual move, Bloomberg is skipping early voting states, focusing instead on the larger states such as California, Florida and Texas that vote on March 3 - Super Tuesday - and beyond.
Ranked by Forbes as the eighth-richest American with an estimated worth of $US53.4 billion, Bloomberg has previously been praised within the party for his advocacy and philanthropy on climate change and in fighting gun violence. He served as mayor of New York from 2002 to 2013.
Bloomberg has poured hundreds of millions of dollars of his own wealth into trying to win the nomination, spending millions on television advertisements.
Elizabeth Warren
The 70-year-old US senator from Massachusetts saw her standing in opinion polls skyrocket and then fade in the months leading up to the early primary contests. Warren finished third in Iowa, is likely to finish fifth in South Carolina, and was fourth in Nevada and New Hampshire, which neighbours her home state.
A fierce critic of Wall Street, she has based her campaign on a populist anti- corruption message and argues the country needs "big, structural change."
Despite her liberalism, she has been criticised by some progressives for not fully embracing the "Medicare for All" healthcare plan that would eliminate private insurance in favour of a government-run plan. Some moderates, on the other hand, view her policies, which include a tax on the super-rich, as too extreme.
Even so, Warren contends that she is the best candidate to unite the party's warring moderate and progressive factions.
Tulsi Gabbard
The Samoan-American congresswoman from Hawaii is the first Hindu to serve in the US House of Representatives and has centreed her campaign on her anti-war stance.
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Despite finishing in all four early primary states near the bottom of the heap, Gabbard, an Iraq war veteran, has vowed to continue to campaign.
Gabbard's populist, anti-war approach has won her fans among both the far left and the far right.
Gabbard, 38, has been engaged in a public feud with 2016 Democratic presidential nominee Hillary Clinton. She sued Clinton for defamation, seeking at least $US50 million in damages for suggesting last year that one of the party's White House contenders was a "Russian asset."
- BBC / Reuters
