Getting a playful headlock from John Kerry as he mugged for a documentary crew at a house party, accidentally falling from the stage at a Wesley Clark event, winding up as the straight man in an election-night segment on “The Daily Show’’ — these are some of the things I’ll never forget about covering the 2004 New Hampshire presidential primary.

Still, the first thing I often picture from those days is a campaign volunteer named McLane Heckman trying — and not quite succeeding — to help former US senator Carol Moseley Braun put on her coat, after hosting a gathering for her. “W-w-w-wait!’’ she said, stopping him with a warm laugh. “First, find the girl’s arm.’’

Heckman’s dad grinned. Though his son had organized a fund-raising dinner, been Moseley Braun’s guest at a televised debate, and spread her message door-to-door, he was just 15 and had not yet been to a prom.

That was a Friday night in December 2003, and I was there to write about Heckman, a devoted volunteer for Moseley Braun, a long-shot candidate in a Democratic field then paced by Howard Dean. When she traveled the state to talk to voters, Heckman sometimes rode along — “a reflection of his devotion to the campaign,’’ I wrote, “but also of needing a ride. He can quote her platforms from heart, but he is too young to drive.’’

Heckman, who had arrived in New Hampshire only recently after his military family was evacuated from Bahrain in the run-up to the Iraq war, encapsulated so much of what appealed to me about New Hampshire’s primary. Even candidates polling in the single digits could develop committed supporters, age was not a prerequisite for involvement, and regular people could host ambassadors in their living rooms.

I was 24 and had been at the Concord Monitor a few months. Everyone in the newsroom had at least one candidate to track, and Moseley Braun essentially represented a last-round pick, a reflection of my junior standing.

Some reporters might have been disappointed, but I’ve always been drawn to offbeat slice-of-life stories, and Moseley Braun’s distant standing freed me to write more about the human side of the primary, and less about the horse race or the fine-grain detail of her policies.

Moseley Braun had once been ascendant, the first African-American woman elected to the Senate, but questions about sloppy bookkeeping and a friendship with the family of a Nigerian dictator tarnished her image and made her a one-term senator. After returning from a stint as President Clinton’s ambassador to New Zealand, she was running for president at least partly to reclaim her image.

I liked the quixotic nature of her campaign, and it helped that in person she was smart and funny, adding a splash of charisma to a starchy field. On the trail, she had a compelling story to tell — as the only woman in the race, as the only one who had experienced Jim Crow segregation — and from the back of the polls was freer than competitors to stake out bold positions on issues like health care, gay marriage, and Iraq.

For Heckman, whose parents were leaning toward other candidates, Moseley Braun seemed to crackle through the TV when he first glimpsed her in a debate. He was certain that if she could just overcome her visibility problem, she would surge. Indeed, after he invited her to his high school, she electrified the audience, and a dozen other teens — including some volunteering for Dean — signed on to help.

Out of necessity, her campaign had a low-budget charm; I remember the night of the party, someone hit “play’’ on a CD cued up to Des’Ree’s inner-strength anthem “You Gotta Be,’’ before Moseley Braun bounded into a living room where a cluster of people — half of them not yet old enough to vote — waited around the coffee table. If she was disappointed, she didn’t show it, winning over the room in a spirited, wide-ranging discussion. By the end of the night, McLane Heckman beamed as his dad complimented Moseley Braun and said he was coming around.

With a thousand McLane Heckmans, Moseley Braun might have made a dent. Instead, she dropped out 12 days before the primary and endorsed Dean. I imagined then that I was the second most forlorn person in the Granite State. A longform profile I’d worked on for weeks was supposed to run the next day. It got scrapped. I could only imagine how Heckman felt.

That was 12 years ago, and I found him recently through Facebook. Heckman remembered 2003-04 as a period of “hope and possibility.’’ Mere months after being evacuated from the Middle East, he had gone “from being yet another uprooted military brat trying to fit in to asking presidential candidates about how they would reverse the [Bush] administration’s failures.’’

“Though I remain convinced these were opportunities I only really could have had in New Hampshire,’’ he wrote, “my first real exposure to the American electoral system made me feel that if everyone gave a least a little energy to hearing what the candidates had to say independent of their financial connections and resources, or despite them, our electoral system would be much stronger.’’

When Moseley Braun dropped out, she called him personally. They stayed in touch for a time, and she wrote him college recommendations a few years later. Now 27, Heckman taught English in Istanbul and earned a master’s degree from the University of London before following his partner to Berlin; he plans to apply for a doctorate in gender studies.

Following the primary from Germany, he recognizes it as a uniquely American privilege, but he laments the horse-race focus and shudders at the reductive sound bites that reach Europe.

Active now on LGBTQ issues, Heckman traveled to Geneva recently to meet with US Ambassador Keith Harper, the country’s representative to the UN Human Rights Council, to pitch ways for the United States “to engage in the struggle for gender identity and expression rights on the international stage.’’

For a moment, he was intimidated. But then he thought about being 15, hosting Ambassador Moseley Braun in his living room, and “the memories of her kindness and down-to-earth attitude’’ gave him confidence, all these years later.

Eric Moskowitz can be reached at eric.moskowitz@globe.com. Follow him on Twitter @GlobeMoskowitz.