2024 Democratic Party presidential primaries

From January 23 to June 8, 2024, presidential primaries and caucuses were organized by the Democratic Party to select delegates to determine the party's nominee for president in the 2024 United States presidential election. The elections took place in all U.S. states except Florida and Delaware, in the District of Columbia, in five U.S. territories, and as organized by Democrats Abroad.

On April 25, 2023, incumbent President Joe Biden announced that he would seek re-election in 2024. Eventually, three main primary opponents emerged: Self-help author Marianne Williamson, who declared her candidacy in March 2023; anti-vaccine activist and environmental attorney Robert F. Kennedy Jr., who launched his candidacy in April 2023; and U.S. Representative Dean Phillips of Minnesota, who announced his candidacy in October 2023. Phillips argued that Biden would be a weak general election candidate due to his age and his low approval ratings. Additionally, the Uncommitted National Movement, supported by some Muslim Americans, Arab Americans, progressives, and socialists began advocating in 2024 for an "uncommitted" vote in protest against Biden due to his support for Israel during the Gaza war.

Kennedy withdrew from the Democratic primaries in October 2023 to run as an independent candidate. On March 6, 2024, Phillips suspended his campaign and endorsed Biden. After stopping and restarting her campaign, Williamson ended her campaign for the final time on July 29, 2024. Phillips received the second-highest number of delegates in the primaries of any candidate (four delegates gained).

Biden became the presumptive presidential nominee of the Democratic Party on March 12, 2024 by securing over 1,968 pledged delegates. Ultimately, Biden withdrew from the race on July 21 after losing the support of many Democrats because of age and health concerns following a debate with Donald Trump. He immediately endorsed Vice President Kamala Harris to replace him as the party's presidential nominee. By the next day, Harris had secured the non-binding support of enough uncommitted delegates that were previously pledged to Biden to make her the party's presumptive nominee. Harris officially became the party's presidential nominee following a virtual roll call with the support of approximately 97.21% of all the delegates. Harris and her running mate, Tim Walz, would go on to lose the election to the Republican ticket of Donald Trump and JD Vance.