Arguably it was Donald Trump who launched the political career of John Fetterman, the Pennsylvania Democrat who clinched the state’s US Senate seat in Tuesday’s election.

In the days after the 2020 presidential vote, the former US president infamously claimed there had been widespread election fraud, including in Pennsylvania, where Fetterman was lieutenant governor.

Fetterman disagreed.

“The president is no different than any other random internet troll,” the Democrat said in an interview with MSNBC, in a comment that delighted Trump opponents in the US and beyond.

When Trump later said he would sue Pennsylvania over alleged, but nonexistent, voter fraud, Fetterman’s response was equally succinct.

​​“The president can sue a ham sandwich,” he said.

As Americans remained glued to their screens awaiting the results of the 2020 election – Biden was only declared the winner four days after election day, after states including Pennsylvania painstakingly counted their votes – Fetterman’s televised lampooning of Trump’s increasingly unhinged claims brought him a national profile, which he would channel into his Senate campaign.

It also probably didn’t hurt that Fetterman is instantly recognisable. At 6ft 8in tall, and almost permanently dressed in a hoodie and shorts, the tattooed, bald, goateed Fetterman is easy to pick out of a crowd.

His appearance, and his background as the long-serving mayor of the small, struggling Pennsylvania steel town of Braddock, lends itself to his public persona, too: a blue-collar Democrat, someone who is tough, no nonsense, who will stick up for the regular guy.

Fetterman brought that aura and popularity to his Senate run, and in the Democratic primary the 53-year-old led the polls by 20% almost throughout the race, as his progressive stance on increasing the minimum wage, abortion rights, healthcare and marijuana gained widespread support.

Everything, it seemed, was going perfectly, until 13 May, when Fetterman had a stroke. Doctors removed a blood clot from his brain and implanted a pacemaker, and Fetterman won the Democratic primary, in absentia, four days later, but it has been a long recovery.

Fetterman said he “​​almost died” from the stroke and he was kept away from the campaign trail for months before he resumed limited public appearances in August, but he has continued to have difficulty speaking and processing others’ speech.

In a debate with Mehmet Oz, the Republican candidate, in October, two 70in screens were installed in front of the candidates, which carried transcriptions of the moderator’s questions and Oz’s responses.

“I sometimes will hear things in a way that’s not perfectly clear. So I use captioning so I’m able to see what you’re saying,” Fetterman said during an interview with NBC in October. “And every now and then I’ll miss a word. Or sometimes I’ll maybe mush two words together. But as long as I have captioning, I’m able to understand exactly what’s being asked.”

Fetterman’s appearance in the debate, in which he stumbled over his phrasing and struggled to get out rebuttals to Oz’s own points, had Democrats worried, and the polls tightened in the days before the vote.

“Let’s also talk about the elephant in the room,” Fetterman said during the debate, as he tried to get ahead of any criticism.

“I had a stroke. He never let me forget that.”

Fetterman was referring to Oz, whose campaign launched unsavory attacks, with one Oz aide, Rachel Tripp, claiming Fetterman might not have had a stroke if he “had ever eaten a vegetable in his life”.

For his part, during the campaign Fetterman and his team channeled the straight-talking, playful personality he showcased in the wake of the 2020 election, skewering Oz over everything from the Republican’s tone-deaf complaints over the price of “crudités” to Oz’s lack of connection to Pennsylvania. (Oz lived in New Jersey for decades before apparently moving to Pennsylvania, into a house owned by his wife’s family, in October 2020. He announced his candidacy for the Senate two months later.)

Fetterman’s image as an earthy, working-class hero enabled him to position himself as the opposite to Oz’s elitist, rich man vibe, and to appeal to a broad range of Pennsylvanians, although the truth isn’t quite that simple.

The Democrat has an MBA from the University of Connecticut and a master’s from Harvard, and has acknowledged growing up in a “cushy” environment made possible by his father’s successful insurance business. Fetterman has said he received financial assistance from his parents for almost all of his 13 years as Braddock’s mayor – the job only paid $150 a month – until he became Pennsylvania’s lieutenant governor in 2019.

There seems little disingenuous about Fetterman, however, who chose not to move into the lieutenant governor’s mansion when elected, instead remaining in Braddock, where he lives, as he has often told crowds at rallies, opposite a steel mill. His passion for the town is visible on his right forearm, where nine tattoos mark the dates that people were killed “through violence” in Braddock while he was mayor.

Having spent the bulk of his political career in charge of a town of 2,000 people, Fetterman will now represent Pennsylvania’s population of nearly 13 million. As he spoke to the crowd in the early hours of Wednesday, it seemed like a challenge he was ready for.

“This campaign has always been about fighting for anyone that ever got knocked down that got back up. This race is for the future of every community across Pennsylvania, for every small town or person that ever felt left behind,” Fetterman said.

“We bet on the people of Pennsylvania and you never let us down.”