US Senator Bernie Sanders says he will run again for president in 2020, making a second attempt to win the Democratic Party’s nomination.
The senator from Vermont, 77, became a progressive political star in 2016 although he lost his candidacy bid.
“We began the political revolution in the 2016 campaign, and now it’s time to move that revolution forward,” he said.
An outspoken critic of President Donald Trump, Mr Sanders has described him as a “pathological liar” and “racist”.
Mr Sanders – an independent who caucuses with the Democrats – is one of the best-known names to join a crowded and diverse field of Democratic candidates, and early polls suggest he is far ahead.
His calls for universal government-provided healthcare, a $15 national minimum wage and free college education electrified young voters, raised millions of dollars in small donations and are now pillars of the party’s left-wing.
Mr Sanders was first elected to Congress in 1990 and has served as Vermont senator since 2007.
He was runner-up in the 2016 Democratic primary, losing out to Hillary Clinton.
Elizabeth Warren, Kirsten Gillibrand, Kamala Harris, John Delaney and Julian Castro are among those who have also announced their intention to run.
The 2020 Democratic presidential primary will be the first time more than one woman has competed for the party’s nomination.
If Mr Sanders is successful in securing the nomination, he will become the oldest presidential candidate in US history.