Rep. Seth Moulton is set to end his 2020 presidential bid after failing to gain traction in the polls or with donors.

The three-term congressman plans to say in a speech later on Friday that he feels confident that he “raised issues that are vitally important to the American people and our future,” and he will pledge to campaign vigorously for the eventual Democratic nominee.

The announcement caps a short-lived campaign in which Moulton, a Marine veteran, opened up about dealing with post-traumatic stress from four tours in Iraq. His campaign focused on foreign policy, national security and mental health, as well as helping veterans.

“That’s what this campaign has been about and I’m so proud of what we’ve done,” Moulton will say at the Democratic National Committee summer meeting. “But today, I want to use this opportunity, with all of you here, to announce that I am ending my campaign for president. 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’s decision to drop out comes ahead of the third Democratic presidential debate next month. The Massachusetts congressman, long mentioned as a possible presidential candidate, never registered in any of the 39 qualifying polls used by the DNC to determine would would qualify for the debate stage.

Moulton struggled at the bottom of the packed Democratic primary field in both polling and fundraising. He is the fourth Democrat to drop out of the race, after Rep. Eric Swalwell, former Colorado Gov. John Hickenlooper, and Washington Gov. Jay Inslee. Moulton plans to run for reelection.