WASHINGTON/SAN FRANCISCO (Reuters) - U.S. Representative Seth Moulton, who mounted a long-shot bid for the 2020 Democratic presidential nomination, ended his campaign on Friday, warning that the party must now decide how far left it wants to move.

“Today, I want to use this opportunity ... to announce that I am ending my campaign for president,” Moulton said in a speech before a Democratic National Committee meeting in San Francisco, drawing polite applause.

“Though this campaign is not ending the way we hoped, I am leaving this race knowing that we raised issues that are vitally important to the American people and our future.”

Moulton, a 40-year-old Iraq War veteran who plans to seek re-election to the Massachusetts district he represents, failed to garner the support he needed to qualify for any of debates. Without appearing in those nationally televised events, he had little hope of gaining traction.

He is the third Democrat to end a presidential campaign this month. Washington Governor Jay Inslee dropped out of the race earlier this week, and former Colorado Governor John Hickenlooper did so the week before.

In an odd twist, Moulton’s announcement appeared to attract the attention of President Donald Trump, who was under intense criticism on Friday after his latest salvo in the U.S.-China trade war helped send global markets plummeting.

Trump, appearing to joke, wrote on Twitter, “The Dow is down 573 points perhaps on the news that Representative Seth Moulton, whoever that may be, has dropped out of the 2020 Presidential Race!”

Moulton stopped short of endorsing one of his rivals for the nomination but said the crowded race with more than 20 Democrats appeared to have narrowed. The nominee will take on Trump, the likely Republican nominee, in November 2020.

“I think it’s evident that this is now a three-way race between (former Vice President Joe) Biden, (U.S. Senator Elizabeth) Warren and (U.S. Senator Bernie) Sanders, and really it’s a debate about how far left the party should go,” Moulton told the New York Times in an interview ahead of his announcement.

Biden represents the more centrist faction of the Democratic Party, while Warren, of Massachusetts, and Sanders, of Vermont, back more liberal policies.

Other Democrats who fail to qualify for the third debate, which will be held on Sept. 12-13 in Houston, may also feel pressure to exit the race. Candidates must have at least 130,000 unique donors and reach 2% in four opinion polls by Aug. 28 to qualify.

Those who have yet to qualify include U.S. Senators Kirsten Gillibrand of New York and Michael Bennet of Colorado and Montana Governor Steve Bullock.

Moulton built his political career by challenging the party’s establishment. After the Democrats regained control of the U.S. House of Representatives in 2018, Moulton helped organize opposition to Representative Nancy Pelosi’s bid to again become House speaker. He failed at that effort.

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He used his presidential campaign to draw attention to veterans issues, including post-traumatic stress disorder, or PTSD, and access to healthcare.