Ten Republican hopefuls are seeking their party's nomination for the November 2024 election to take on US President Joe Biden, who faces two long-shot challenges to be the Democratic Party's nominee. Here is a list of the contenders.

Republican Party
Donald Trump

Donald Trump, 77, has embraced his indictments in four separate criminal cases - unprecedented for a former US president - which have boosted his popularity among Republicans and helped to make him far and away the front-runner in his party's race for the presidential nomination.

Trump has called the indictments part of a politically motivated witch hunt to thwart his pursuit of a second four-year term, an assertion the Justice Department has denied. In a sign of his extraordinary hold on his party, just two rivals at the first Republican presidential debate on Aug. 23 said they would not support him as the nominee if he were convicted.

Trump has vowed to enact tougher immigration restrictions and harsher curbs on trade with China, and to carry out political reprisals against those he perceives have wronged him. He has a firm grip on his party's right wing but may struggle to get moderates and independents to support him in a general election should he win the Republican nomination.

Ron DeSantis

After a glitch-filled campaign launch in May on Twitter, now called X, DeSantis has positioned himself to the right of Trump on a number of key social issues such as abortion. But his well-funded campaign has struggled to gain traction, and his top donor has said he will not give the Florida governor more money unless he adopts a more moderate approach.

DeSantis, 44, is Trump's top rival, but remains far behind the former president in opinion polls. He has fired staff and rebooted his campaign several times since May, but those steps have done little to boost his candidacy. DeSantis' campaign says it is focused on stopping Trump in Iowa, where the party will hold its first nominating contest in January.

Mike Pence

Trump's vice president has broken with his former boss over Trump supporters' Jan. 6, 2021, attack on the US Capitol as Pence was inside presiding over Congress' certification of Biden's 2020 victory. Pence, 64, says, "history will hold Trump accountable" for his role in the attack.

A staunch conservative, the former Indiana governor is appealing directly to the evangelical Christian community, but his campaign has struggled to raise money and he is stuck in the low single digits in opinion polls.

Vivek Ramaswamy

A former biotechnology investor and executive, Ramaswamy, 38, started a firm in 2022 to pressure companies to abandon environmental, social and corporate governance initiatives. The political outsider has stoked grassroots chatter as a potential alternative to Trump. He is a fervent supporter of the former president, and says he would pardon Trump should he win the White House.

Nikki Haley

A former South Carolina governor and Trump's ambassador to the United Nations, Haley, 51, has emphasised her relative youth compared to Biden and Trump as well as her background as the daughter of Indian immigrants.

Haley has gained a reputation in the Republican Party as a solid conservative who has the ability to address issues of gender and race in a more credible fashion than many of her peers. She has also pitched herself as a stalwart defender of American interests abroad. She has low single-digit support among Republicans, according to opinion polls.

Tim Scott

The only Black Republican US senator has low name recognition outside his home state of South Carolina, but his optimism and focus on unifying his divided party have helped him draw a contrast with a more aggressive approach from Trump and DeSantis. Scott supporters, however, acknowledge that while his sunny demeanor is a selling point, it may not be enough to win. Scott, 57, attracted 1 per cent support among Republicans, according to Reuters/Ipsos polling.

Asa Hutchinson

The former Arkansas governor launched his bid for the White House in April with a call for Trump to step aside to deal with his first indictment. Hutchinson, 72, has touted his experience, leading a deeply conservative state as proof he can deliver on policies Republican voters care about, citing tax cuts and job creation initiatives.

Still, his name recognition remains limited outside Arkansas, and he earned no support among Republicans polled by Reuters/Ipsos.

Chris Christie

Christie, 61, advised Trump's White House campaign, but became a vocal critic of the former president after the Jan. 6, 2021, attack. The former New Jersey governor and federal prosecutor has stepped up his verbal attacks as Trump faces a growing number of criminal charges.

Christie has received about 1 per cent support among Republicans in Reuters/Ipsos polls.

Doug Burgum

Burgum 67, is serving his second term as North Dakota's governor after selling his software business to Microsoft Corp in 2001. A proponent of low taxes and fewer regulations, he has sought to portray himself as a traditional conservative with a focus on the economy and national security. One of the least-known contenders, he gets close to zero support in polls.

Will Hurd

A former US congressman, Hurd is a sharp Trump critic and moderate Republican who represented a southern Texas border district until he chose not to seek reelection in 2020. The 46-year-old is the second Black candidate in the Republican race, after Scott.

Democratic Party
Joe Biden

Biden, 80, already the oldest US President ever, will have to convince voters he has the stamina for another four years in the White House, amid concerns about his age and poor approval ratings. Biden allies say he feels he is the only Democratic candidate who can defeat Trump. In announcing his candidacy he declared it was his job to defend American democracy. He does not face a serious threat from a Democratic challenger.

Robert Kennedy Jr.

An anti-vaccine activist, Kennedy, 69, is making a long-shot bid to challenge Biden for the Democratic nomination. He is the son of US Senator Robert F. Kennedy, who was assassinated in 1968 during his own presidential bid. Kennedy was banned from Instagram for spreading misinformation about vaccines and the Covid-19 pandemic, but was reinstated. He lost a legal bid to force YouTube owner Google to reinstate videos of him questioning the safety of Covid-19 vaccines.

Marianne Williamson

The best-selling author and self-help guru has launched her second, long-shot bid for the White House. She ran as a Democrat in the 2020 presidential primary but dropped out of the race before any votes had been cast. She launched her latest campaign on March 23.

Green Party
Cornel West

The political activist, philosopher and academic said in June he would launch a third-party bid for president that is likely to appeal to progressive, Democrat-leaning voters. West is running from the Green Party on ending poverty and guaranteeing housing, and has hired on former Hillary Clinton adviser Peter Daou as campaign manager.