LACONIA, N.H. >> That Sanders fellow was shouting again.

Earlier in the evening at a campaign forum here, he had yelled, unprompted, about Medicare for all. During his introductory statement, he had bellowed about dentures.

Now, as the audience groaned at his attacks on other candidates, he snapped.

“Excuse me! Excuse me!” he thundered. “I’m here to talk, OK?”

The moderator threatened to turn his microphone off. And then Levi Sanders — the son of the Vermont senator this neighboring state knows well — shouted some more.

Throughout his campaign for an open congressional seat here, Sanders has insisted he is his own man.

“I’m not a clone of my father,” he said in a late-night interview after the forum earlier this month. His shirt was rumpled. He looked weary.

But with just weeks to go until his primary in the 1st District, Sanders, 49, still cannot avoid comparisons to his father, Bernie Sanders. His father, who won the 2016 presidential primary in this Live Free or Die state by 22 points. His father, whose booming, sometimes bellicose style on the stump seems to have rubbed off on his son.

Like Bernie Sanders, Levi Sanders is fighting — loudly — for single-payer health care, a $15 minimum wage and tuition-free public college. He vilifies corporate political action committee money. He has asked backers to contribute $27, the same amount his father had touted during his presidential campaign to prove his support came from small donors. On Levi Sanders’ website? A photo of his father, front and center.

Sanders’ campaign, for a House seat in a competitive district, has puzzled everyone from the most enthusiastic Bernie supporters to his 10 Democratic opponents, more than a few of whom seem all too eager to dismiss his candidacy. Some people view him as a firebrand with a quick fuse and a sharp tongue. Others describe him more as a nuisance, who has only gained notice because of his name. Because he lives outside the district, on the other side of this outsider-averse state, he has even been accused of carpetbagging.

Sanders, who is not a lawyer, has made a career in legal services fighting for the less fortunate. But there is no doubt he is a severe underdog in his primary. He worked for his father’s campaign, but in terms of nonfamilial political experience, he has none. Nearly a decade ago, he ran for City Council in Claremont, where he lives, and finished seventh in a field of nine.

Oh, and one more thing: His father has not endorsed him.

Bernie Sanders declined to comment for this article. In an interview in May, he snapped at a question about his son before requesting to go off the record.

“Levi has spent his life in service to low-income and working families, and I am very proud of all that he has done,” he said in a statement earlier this year. “In our family, however, we do not believe in dynastic politics. Levi is running his own campaign in his own way.”

When the senator’s stepdaughter, Carina Driscoll, ran for mayor of Burlington, Vermont, this year — a seat he once held — he did not endorse her either. She lost.

The elder Sanders has four children. Three are from his wife’s previous marriage. Levi Sanders (pronounced LEH-vee) is his only biological child.

The younger Sanders swears he is not upset by his father’s decision not to endorse him.

“He’s always believed, ever since I was little, that I have to stand up on my own,” he said.

Through the end of June, Sanders had raised less than $30,000, a truly meager amount compared with nearly every other candidate in the race. His campaign manager, a 2016 Bernie-or-Buster, has managed only one other campaign. His website is turn-of-the-millennium retro. If Sanders is banking on his name, a brief tour through Portsmouth, on the state’s coast, turned up few voters who were aware he was running.

The district itself carries considerable significance for Democrats this fall.

It is a perennial battleground, with a seat that has alternated between parties — and the same two politicians — for a decade. Though currently held by a Democrat, it went for President Donald Trump by 2 points in 2016, and Republicans see it as a potential target this fall.

Two Republican candidates are competing for their party’s nomination: Andy Sanborn, a state senator, and Eddie Edwards, a veteran and former police chief who was recently endorsed by Rudy Giuliani, Trump’s lawyer. (The president has not yet weighed in on the race.)

On the Democratic side, the field is crowded and varied. There are the front-runners: Maura Sullivan, a former Marine and ex-official in the Obama administration with national support who moved to the district last year, and Chris Pappas, a New Hampshire Executive Council member who has been endorsed by top local Democrats, including Sen. Jeanne Shaheen.

There is the retired trial lawyer, the environmental scientist, the junior politico, the Army veteran, the labor leader, the telegenic businessman and two awe-shucks-we’re-running-because-we-can-ers.

Then there is Levi Sanders.

Sanders, whose mother is Susan Campbell Mott, his father’s girlfriend at the time, has long been a fixture in his father’s political career, appearing with him from the time he was 2. There is, it would seem, perhaps no other person as familiar with the Bernie Sanders brand of anti-establishment, populist progressivism.

During the 2016 presidential campaign, the younger Sanders played a role in the effort to humanize the senator. On Halloween in 2015, the press dutifully captured Levi Sanders and his three children — the White Witch, Sonic the Hedgehog and the Abominable Snowman — as their grandfather loped alongside them. The following January, Sanders introduced his father at a town hall in Wolfeboro.

“The person I’m going to introduce I know just a little, teeny bit, as he’s my father,” he said, leaning into the podium with his father’s wide-armed, two-handed grip.

There are other similarities — in mannerisms, in appearance, in cadence — but the younger Sanders is quick to brush them off.

“I’m 6 foot 2 1/2, and he’s 6 feet!” he said during the post-forum interview.

“I’m a size 14 shoe. He’s an 11 1/2!”

He’s used the lines before (many times).

“I’m a pretty gregarious guy,” he said later. “I think I’m funny.”

So far, he hasn’t made much of an impression on his opponents.

“I don’t know that he brings that much dimensionality to the race,” state Rep. Mindi Messmer, the environmental scientist, said in an interview in Portsmouth.

In conversations with voters, many were similarly unaffected.

“Cool,” David McKinniss, 62, a fan of Bernie Sanders, said when informed the senator’s son was running. “Is it going to be another Kennedy dynasty?”

Sanders, it should be noted, does have his supporters. Earlier this year, he was endorsed by Rep. Ro Khanna of California. The two had been chatting on Twitter, Khanna said in a recent phone interview, and Sanders expressed support for some of his positions, including single-payer health care.

After the forum, at a hotel on Lake Winnipesaukee, Sanders acknowledged that his father’s legacy in New Hampshire helped him “get in the door.”

But he rejected the suggestion that it was hard to get voters to see him as anything other than his father’s son. During his 18-year career in legal services, he has seen people “who are just getting beaten up and crushed by the system.” He said he decided to run for office because “I feel like I’d be a very strong advocate for those folks.”

“The reality is I am my own person,” he said. “My father didn’t represent people in legal services.”

As the night wore on, it became increasingly clear that Sanders was also prone to unusual turns of phrase.

When told that he seemed less than relaxed, he replied: “I’m not stiff. I do yoga.”

Asked to define himself, he offered, “I am not a Romulan. I am not a Vulcan.” (“Star Trek!” he cried, when his reference was met with a blank stare.)

He tried again. “I am a sentient being,” he said.

By that point, he was the only candidate left in the dimly lit hotel lobby. He stayed a little longer. Then he got in his car and drove home.

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