She was a former state prosecutor and a US senator whose encouraging poll numbers and early popularity raised the potential prospect of voters electing the country's first African-American woman as president.

But by the time she dropped out of the race for the Democratic nomination, Kamala Harris had run out of money and had faced a virtual mutiny among her campaign staff as internal division and strategy failures reached a boiling point.

Ms Harris, who endured 11 months on the campaign trail, including several nationally televised debates, announced to her supporters and staff with "deep regret" and "deep gratitude" that she "simply doesn't have the financial resources we need to continue."

"I'm not a billionaire", she said. "I can't fund my own campaign. And as the campaign has gone on, it's become harder and harder to raise the money we need to compete."

The announcement follows reports that billionaire Michael Bloomberg spent nearly $60m on advertising in recent weeks, and that Tom Steyer, another billionaire who has spent more than $60m on ads since July. Both men are white.

The Democrat challengers to Trump in 2020 Show all 25 1 /25 The Democrat challengers to Trump in 2020 The Democrat challengers to Trump in 2020 Bernie Sanders The Vermont senator has launched a second bid for president after losing out to Hilary Clinton in the 2016 Democratic primaries. He is running on a similar platform of democratic socialist reform Getty The Democrat challengers to Trump in 2020 Joe Biden The former vice president recently faced scrutiny for inappropriate touching of women, but was thought to deal with the criticism well and has since maintained a front runner status in national polling EPA The Democrat challengers to Trump in 2020 Elizabeth Warren The Massachusetts senator is a progressive Democrat, and a major supporter of regulating Wall Street Reuters The Democrat challengers to Trump in 2020 Amy Klobuchar Klobuchar is a Minnesota senator who earned praise for her contribution to the Brett Kavanaugh hearings Getty The Democrat challengers to Trump in 2020 Michael Bloomberg Michael Bloomberg, a late addition to the 2020 race, announced his candidacy after months of speculation in November. He has launched a massive ad-buying campaign and issued an apology for the controversial "stop and frisk" programme that adversely impacted minority communities in New York City when he was mayor Getty Images The Democrat challengers to Trump in 2020 Tulsi Gabbard The Hawaii congresswoman announced her candidacy in January, but has faced tough questions on her past comments on LGBT+ rights and her stance on Syrian President Bashar al-Assad Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Pete Buttigieg The centrist Indiana mayor and war veteran would be the first openly LGBT+ president in American history Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Deval Patrick The former Massachusetts governor launched a late 2020 candidacy and received very little reception. With just a few short months until the first voters flock to the polls, the former governor is running as a centrist and believes he can unite the party's various voting blocs AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Beto O'Rourke The former Texas congressman formally launched his bid for the presidency in March. He ran on a progressive platform, stating that the US is driven by "gross differences in opportunity and outcome" AP The Democrat challengers to Trump in 2020 DROPPED OUT: Kamala Harris The former California attorney general was introduced to the national stage during Jeff Sessions’ testimony. She has endorsed Medicare-for-all and proposed a major tax-credit for the middle class AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Bill De Blasio The New York mayor announced his bid on 16 May 2019. He emerged in 2013 as a leading voice in the left wing of his party but struggled to build a national profile and has suffered a number of political setbacks in his time as mayor AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Steve Bullock The Montana governor announced his bid on 14 May. He stated "We need to defeat Donald Trump in 2020 and defeat the corrupt system that lets campaign money drown out the people's voice, so we can finally make good on the promise of a fair shot for everyone." He also highlighted the fact that he won the governor's seat in a red [Republican] state Reuters The Democrat challengers to Trump in 2020 DROPPED OUT: Cory Booker The New Jersey Senator has focused on restoring kindness and civility in American politics throughout his campaign, though he has failed to secure the same level of support and fundraising as several other senators running for the White House in 2020 Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Wayne Messam Mayor of the city of Miramar in the Miami metropolitan area, Wayne Messam said he intended to run on a progressive platform against the "broken" federal government. He favours gun regulations and was a signatory to a letter from some 400 mayors condemning President Trump's withdrawal from the Paris Climate Accord Vice News The Democrat challengers to Trump in 2020 DROPPED OUT: Kirsten Gillibrand The New York Senator formally announced her presidential bid in January, saying that “healthcare should be a right, not a privilege” Getty The Democrat challengers to Trump in 2020 DROPPED OUT: John Delaney The Maryland congressman was the first to launch his bid for presidency, making the announcement in 2017 AP The Democrat challengers to Trump in 2020 DROPPED OUT: Andrew Yang The entrepreneur announced his presidential candidacy by pledging that he would introduce a universal basic income of $1,000 a month to every American over the age of 18 Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Julian Castro The former San Antonio mayor announced his candidacy in January and said that his running has a “special meaning” for the Latino community in the US Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Marianne Williamson The author and spiritual adviser has announced her intention to run for president. She had previously run for congress as an independent in 2014 but was unsuccessful Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Eric Swalwell One of the younger candidates, Swalwell has served on multiple committees in the House of Representatives. He intended to make gun control central to his campaign but dropped out after his team said it was clear there was no path to victory Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Seth Moulton A Massachusetts congressman, Moulton is a former US soldier who is best known for trying to stop Nancy Pelosi from becoming speaker of the house. He dropped out of the race after not polling well in key states Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Jay Inslee Inslee has been governor of Washington since 2013. His bid was centred around climate change AFP/Getty The Democrat challengers to Trump in 2020 DROPPED OUT: John Hickenlooper The former governor of Colorado aimed to sell himself as an effective leader who was open to compromise, but failed to make a splash on the national stage Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Tim Ryan Ohio representative Tim Ryan ran on a campaign that hinged on his working class roots, though his messaging did not appear to resonate with voters Getty The Democrat challengers to Trump in 2020 DROPPED OUT: Tom Steyer Democratic presidential hopeful billionaire and philanthropist Tom Steyer is a longtime Democratic donor AFP/Getty

Her departure leaves one less person of colour in the remaining field of 15 Democratic contenders, of which 10 are white; all six candidates who qualified for December debates so far are white.

Before she announced the end of her campaign, Ms Harris was the only non-white candidate to qualify for that debate.

Her departure from the race also has underscored allegations of racism and sexism directed at the media status quo as her campaign struggled to gain a foothold among other Democratic contenders.

Ms Harris said her campaign "uniquely spoke to the experiences of Black women and people of colour — and their importance to the success and future of this party. Our campaign demanded no one should be taken for granted by any political party."

"We will keep up that fight because no one should be made to fight alone", she said. "And I believe our campaign showed every child in America — regardless of their colour or gender — that there are no limits to who can lead and hold positions of power in our country."

Kamala Harris calls Tulsi Gabbard apologist for Syrian president who kills his citizens 'like cockroaches'

Ms Harris's political rise began as a San Francisco attorney general, followed by her election to California state attorney general and the US senate. She became only the second black woman to enter the US Senate when she took office in 2017.

But as soon as she entered the race, Ms Harris endured criticism for inconsistent messaging on health care and criminal justice, vacillating between a progressive-minded reformist and a safer, more moderate candidate that could compete alongside more conservative Democrats like Joe Biden.

She told donors she was "not comfortable" with a Medicare-for-All plan and removed her support for a bill sponsored by Vermont Senator Bernie Sanders, among her campaign rivals.

Among her biggest political challenges was a plan to navigate a progressive criminal justice platform while answering for her record as a "smart on crime" prosecutor.

She rose to power as a top prosecutor amid a climate of progressive organisers and politicians drawing bipartisan reform aimed at addressing vast racial disparities in the criminal justice system.

Kamala Harris asks students if they've trained for school shooting

But her record as a prosecutor included harsh penalties for marijuana offences and threats to prosecute children as part of an anti-truancy push. She also has maintained her personal opposition to the death penalty, but as California's top prosecutor she said she would fight to maintain it.

Shortly after announcing her candidacy, she said: "The bottom line is the buck stops with me, and I take full responsibility for what my office did."

A New York Times op-ed, titled "Kamala Harris Was Not a Progressive Prosecutor," said if the senator "wants people who care about dismantling mass incarceration and correcting miscarriages of justice to vote for her, she needs to radically break with her past."

Ms Harris revealed a platform that aimed to eliminate the death penalty, cash bail and private prisons, building on transformative policies she has supported as a senator.

She delivered arguably the most memorable blow on the debate stage, where she stunned Mr Biden for his defence of segregationist politicians and opposition to desegregation efforts in public schools. During a June debate, Ms Harris said: "There was a little girl in California who was part of the second class to integrate her public schools, and she was bused to school every day, and that little girl was me."

Mr Biden cut his response short before his time was up.

It was a critical attack on the centrist call for "civility" while underlining crucial priority differences among the candidates, shaped largely by perspectives informed by their race.

Her debate appearance attracted significant media attention and helped spike poll numbers in her favour, hitting 20 per cent at its peak.

But her rivals campaigned on more-dramatic policy proposals while she championed herself as a pragmatist, introducing policies that relied on assumptions among a voter base that remained divided.

She faced unanticipated challenges trying to build support among non-white voters by focusing on states like South Carolina and California, while rivals gained traction elsewhere.

Joe Biden left red-faced after forgetting Kamala Harris is African-American

By the third quarter of 2019, contributions to the campaign slowed while it continued to burn through its treasury.

Ms Harris had spent more than $1.41 for every dollar raised, according to reports, and was forced to lay off staff after moving offices to Baltimore, Maryland ahead of preparation for a crucial campaign in Iowa.

And within the last week, press reports charted the chaos within her campaign as it neared 2020.

A devastating November resignation letter obtained by the New York Times revealed internal division among campaign staff led by Ms Harris' sister and campaign chief Maya Harris — an adviser for Hillary Clinton on her 2016 campaign — and campaign manager Juan Rodriguez, who failed to answer questions about strategy and finances ahead of Iowa, according to the letter.

In her resignation letter, now-former state operations manager Kelly Mehlenbacher said she had "never seen a staff treated so poorly."

She said: "Because we have refused to confront our mistakes, foster an environment of critical thinking, and honest feedback, or trust the expertise of talented staff, we find ourselves making the same unforced errors over and over."

Ms Harris had abruptly cancelled a high-profile fundraiser in New York, scheduled for Tuesday, before announcing the suspension of the campaign.

Among Democrats' biggest hurdle in 2020 is demonstrating an ability to beat Donald Trump.