Moulton is clearly a long shot, best known at this point for his failed attempt to block Nancy Pelosi as speaker, which angered liberals across the country and back home in Massachusetts. But his calculus—and that of other more moderate, less well-known candidates—is that the party is veering too far left for its own good in an election against Trump.

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Before he first won his House seat, in 2014, Moulton was a Marine who served four tours in Iraq and was awarded the Bronze Star.

His next stop is South Carolina. Then Iowa. Then Nevada. And back and forth often to New Hampshire, which is only about a 45-minute drive from his condo in Salem.

He knows people will dismiss his chances, but he remembers being 53 points down in the first poll in his primary against a nine-term congressman. A win was “statistically impossible,” he said his pollster told him, a few months before he won.

Moulton likes to make a point of saying that he doesn’t tell war stories. Somewhat famously, he never mentioned the medals he won until The Boston Globe reported on them, long after he won his 2014 primary. But he makes having been at war, and in command of a platoon in combat, a constant part of the story he tells, and how he thinks about getting into 2020.

Read: Nancy Pelosi wouldn’t cut a deal that would have ensured her speakership

“I think Donald Trump is a lot harder to beat than most Democrats think. But I’m also quietly confident that I can beat him, and I don’t think it’ll be the hardest thing that I do in my life,” he said.

Moulton has been worried for years that people haven’t been paying attention to how much of an immediate threat Trump is, ever since he and other members of the House Armed Services Committee took a flight on the so-called Doomsday Plane in early 2017, a few months after the inauguration.

The Cold War has been over for 28 years, but it’s still the plan to have the president and top officials wait out the mushroom clouds from the air in the event of nuclear war, leading the response for whatever is left of America.

Air Force officials showed off the technology. Moulton says much of it looked left over from the 1950s. They stressed all the ways that they couldn’t be hacked. He can’t discuss the details, but they walked the committee members through what Moulton calls “a frighteningly realistic” scenario of events, and how quickly they could escalate into missiles being launched.

“The system’s basically foolproof,” he recalled one of his older House colleagues saying to him.

After he told me the story, he finished with this line: “I said to myself, Unless the guy at the top is a fool.”

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Moulton named the group he created to promote Democratic veterans for House races the Serve America PAC. The name is meant to reflect the mentality of a Harvard undergrad from a nonmilitary family who enlisted after staring at the names on a memorial wall in the campus chapel and talks about running for president as the continuation of his service.