Elizabeth Warren has sharply raised the stakes in the battle to become the Democrats’ 2020 challenger to Donald Trump, dominating much of the party’s first official debate with a promise to fight for voters “as hard as I fight for my own family”.

On a night with 10 hopefuls on the stage and each seeking to make an impact, the senator from Massachusetts was clearly the top seed, albeit in the absence of Joe Biden and Bernie Sanders, who will appear on Thursday. Ms Warren seized on that opportunity, answering the first question of the night with a strong defence of her views on the economy.

Was her vision, which includes support for Medicare for All and a Green New Deal, potentially risky, she was asked.

“I think of it this way. Who is this economy really working for? It’s doing great for a thinner and thinner slice at the top. It’s doing great for giant drug companies,” she replied. “It’s just not doing great for people who are trying to get a prescription filled.”

At least 24 Democrats are seeking to be the candidate to take on Mr Trump, who tweeted from Air Force One on his way to Japan that the debate was “boring”.

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

For the lesser known candidates in particular, such events are a crucial opportunity not only to display their ability to debate, but also reveal something unique and powerful about either their personality or their policies.

With 10 people participating in a format in which questions were asked about immigration, healthcare and foreign policy, seizing such an opportunity was a major challenge. When the Democrats performed this exercise four years ago, there were just five candidates in total – Lincoln Chafee, Hillary Clinton, Martin O’Malley, Bernie Sanders and Jim Webb.

If Ms Warren was fast out of the gates, others sought to catch up, on a night when the broadcast was interrupted by technical problems. Corey Booker, Amy Klobuchar and Tim Ryan will all have considered themselves to have had a decent evening, while Jay Inslee was able to double down on why he believed climate change to be the most important issue.

Most commentators agreed the candidate who most obviously failed to seize the opportunity was Beto O’Rourke, the Texas congressman who impressed many with his challenge last year of Republican Ted Cruz, but who has so far failed to replicate the same traction.

Google revealed the most searched-for candidate during the debate was Mr Booker, a senator from New Jersey, who has so far been disappointed by his failure to poll much higher than three per cent. Asked about gun violence, he was at his most passionate and impressive, calling for tougher regulations of firearms.

Democratic debate: Best moments of night one

“I hear gunshots in my neighbourhood. I think I’m the only one, I hope I am the only one that had seven people shot in their neighbourhood just last week,” said the former mayor of Newark.

He added: “If you need a licence to drive a car, you should need a licence to buy and own a firearm. And not everybody in this field agrees with that, but in states like Connecticut that did that, they saw 40 per cent drops in gun violence and 15 per cent drop in suicides.”

On a day when much of the world was horrified by both the image of a migrant father and his young daughter drowned in the Rio Grande, and the details that have emerged about the conditions at a children’s detention centre in Texas, the candidates were asked about Mr Trump’s immigration policy.

“We have kids laying in their own snot with three-week-old diapers that haven’t been changed. We need to tell the president that is not a sign of strength. That is a sign of weakness,” said Mr Ryan, who is seeking to become the first sitting congressman elected to the White House in more than 100 years. “If you go to Guantanamo Bay, there are terrorists that are held that get better health care than those kids that have tried to cross the border into the United States.”

This was one of the few instances in which Mr O’Rourke was able to land some punches.

In a rather feisty exchange with former Obama administration official Julián Castro, who is pushing a plan that would decriminalise all border crossings and make them a civil offence, Mr O’Rourke defended his work in Congress. “As a member of Congress, I helped to introduce legislation that would ensure we don’t criminalise those seeking asylum. If you are fleeing desperation, I want to make sure you are treated with respect,” he said.

Mr Castro said of the photograph of Alberto Martínez Ramírez, 26, and his 23-month-old daughter, Valeria, dead at the US border: “Watching that image of [Mr Ramirez] and his daughter Valeria was heartbreaking. It should also piss us all off.”

It is unclear how important Wednesday’s debate was. Democrats have at least 12 events scheduled and the first primary, in Iowa, is on 3 February. Thursday’s debate will see if Mr Biden repeats the kinds of gaffes that have wrecked his previous presidential runs.

However, pundits and voters agree that a strong start can be important.

Among those watching events in Miami was Dan Nagler, 36, a lawyer from Miami Beach.

“Just as long as they listen to the people, I guess that’s what it’s all about. You know, listen to the issues, get out into the community, and try to represent the people and not get caught up in one side of the aisle or the other,” he said.

Melanie Martinez, 23, who works at a fashion house in Miami, said he was a registered independent. “I’m not even sure who to support at this point. I support women’s rights, raising the minimum wage, and closing the [migrant] detention centre,” she said.

If Wednesday’s debate was not as memorable as the first Republican debate of the primary season, in which Mr Trump set about attacking his rivals with a rare fervour, it was also largely clear of major blunders or missteps.