2024 US primaries live results

The US primary elections have begun and local Republican and Democratic parties are choosing their candidates ahead of the US presidential election in November.

Donald Trump (Republican) and Joe Biden (Democratic) are clear favourites for selection, although Mr Trump faces opposition from Nikki Haley, his former ambassador to the US. The primary elections move next to arguably the greatest test on Super Tuesday (Mar 5), when about a third of all states in the Union choose their preferred candidate.

States with the largest population have the largest number of delegates (each delegate represents one vote). Texas, for example, one of the most populous states in the US, is allocated 261 Democratic Party delegates and 161 Republican Party delegates. Smaller Wyoming has just 12 Democratic delegates and 14 Republican delegates.

To become their party’s nomination for president, a Republican candidate needs to secure 1,215 delegates to win, while Democrats need 1,968 – a quirk of the two-party, 50-state system. Delegates ratify their chosen candidates at the party conventions in the summer, which act as an unofficial starting gun for the campaign for the White House.