US presidential election 2024: Democrats taking on Joe Biden
Joe Biden has launched his re-election campaign with a video in which he says the country faces a pivotal moment in the 2024 vote.
The Democratic Party, however, still need convincing that he is the best candidate they have.
Polls show about half of Democrats want the party to nominate someone else - although many of those said they will still vote for him.
With the party unlikely to schedule any debates ahead of the primary election, Mr Biden is not expected to face a serious challenge.
So who else is running?
Self-help guru Marianne Williamson was the first Democrat to jump into the 2024 race, with a formal campaign launch in March.
Ms Williamson, 70, is a long-time social justice activist, best-selling author and former "spiritual advisor" to Oprah Winfrey who made her first foray into politics in 2020.
She transfixed audiences with a frenetic performance at two Democratic primary debates, in which she declared that the only way to defeat Donald Trump was to "harness love for political purposes".
The fringe candidate ended that campaign before voting began but she has remained an outspoken voice for the progressive left.
Her 2024 policy platform backs universal government-run healthcare, free childcare, at least $1tn (£800bn) in slavery reparations to black Americans and a federal agency called the Department of Peace.
Ms Williamson is seeking to build her campaign by engaging with young voters on TikTok, where her content has gained millions of views.
Robert F Kennedy Jr
The nephew of President John F Kennedy, who was assassinated, and the son of US Attorney General Bobby Kennedy, who was also killed, launched his campaign for the White House in April.
He is at least the 12th member of the Kennedy dynasty to run for political office, which has helped Mr Kennedy, 69, garner as much as 21% support in recent polls.
The long-time environmental lawyer once won plaudits for campaigning on issues such as clean water, including working to clean up the Hudson River in New York.
But he has been publicly shunned by much of his family over what they call his "tragically wrong" conspiracy theories about vaccines, and embraced by far-right personalities like Alex Jones and Steve Bannon.
Mr Kennedy's vaccine scepticism long predated Covid-19, but he found a new audience during the pandemic, when revenues to the anti-vaccine non-profit he founded in 2011 doubled.
Dennis Kucinich, a former Democratic congressman and two-time presidential candidate who routinely bucked the party line, is managing Mr Kennedy's campaign.