US Senator Bernie Sanders has suspended his presidential campaign, his team said Wednesday, clearing the way for rival Joe Biden to become the Democratic nominee to challenge Republican incumbent Donald Trump in November.

Sanders, a 78-year-old leftist who challenged Hillary Clinton for the nomination in 2016, was holding a staff conference call on Wednesday when he “announced that he is suspending his campaign for president,” his aides said in a statement.

Sanders, who mounted a formidable challenge to Biden in the 2020 race, became the frontrunner early this year only to be eclipsed by a surging former vice president, who holds a substantial lead in the all-important race for delegates who choose the nominee.