Pete Buttigieg, the former Indiana mayor who made an ambitious run for president, has announced he is ending his campaign for the White House.
The 38-year-old became the first openly gay presidential candidate from a major party when he announced he was running for the Democratic nomination.
But despite a successful start, his campaign lost momentum in recent weeks.
His decision to drop out comes ahead of a key day on Tuesday in the Democratic race to take on Trump.
Fourteen states will vote on Super Tuesday, by the end of which staunch left-winger Bernie Sanders could have an unbeatable lead and be a step closer to the nomination.
His departure leaves six Democrats still in the running – Joe Biden, Mr Sanders, Michael Bloomberg, Elizabeth Warren, Amy Klobuchar and Tulsi Gabbard.
Speaking to supporters in his hometown of South Bend, Indiana, Mr Buttigieg stressed the values he said his campaign had hoped to promote.
“And so we must recognise that at this point in the race, the best way to keep faith with those goals and ideals is to step aside and help bring our party and our nation together,” he said. “So tonight I am making the difficult decision to suspend my campaign for the presidency.”