Two nights earlier, his downtown Toronto rally finished with hundreds standing in a serpentine line for 90 minutes, waiting to take a picture with him. Many hadn’t been to a political event before. It’s a scene replicated in towns and cities across the country, with a cross-section of traditional conservatives, trucker-convoy fans and 30-somethings worried about home prices coming out in droves to see Mr. Poilievre. What Mr. Poilievre offered to those crowds is his uncomplicated explanation of what has gone wrong. It’s something he absorbed as a teenager and has preached ever since: Big government overreaches, taking away our personal choice, our economic freedom and our money. Now people are embracing the message – and the messenger. They watched him command stages with a radio-announcer’s voice, a broad smile and a sense of his audience’s frustrations. He talked about teenagers depressed by lockdowns and an unvaccinated mom getting fired. He told the crowd in Toronto about a couple in a trailer park near his home in Greely, who work in a quarry making materials for building houses, but calculate they’ll never afford one of their own. “When the people who build our houses cannot afford to live in them, we have a fundamentally unjust economy, my friends,” he told his listeners. The problem, he said is “big, bossy government” telling people what to do, and spending so much it caused inflation that clobbered ordinary folks. He’s a proselytizer. Mr. Poilievre preaches small-government conservatism while digging both hands into the mucky trenches of partisan politics, ruthlessly pushing aside questioners as Liberal unbelievers. He has spent decades whittling free-market economist Milton Friedman into accessible phrases for main street. Mr. Poilievre watches Prime Minister Justin Trudeau at the House of Commons on Sept. 15.Blair Gable/Reuters There can be no doubt now that Mr. Poilievre has struck a chord with the Conservative Party base and beyond. He has become a social-media and viral-video personality. Hundreds of thousands signed up to back his leadership campaign, handing him a landslide first ballot victory. At 43, the Alberta-raised MP is now Opposition Leader and, by Canadian political tradition, prime-minister-in-waiting. He takes the helm of the Conservatives as the Liberal government of Prime Minister Justin Trudeau, now seven years in power, faces angry veins of pandemic frustration and economic angst fuelled by wallet-stretching inflation. Mr. Poilievre declined an interview request for this piece, and largely avoided sitting down with the media after he solidified front-runner status. The Globe interviewed dozens of current and former colleagues, staff, associates and friends, although many were reticent to be named as it became clearer Mr. Poilievre would be the new Conservative leader. He won the leadership by seizing the momentum of the so-called Freedom Convoy – with its motley mix of pandemic-measure protesters, vaccine opponents and conspiracy theorists – that rolled into Ottawa in January, garnering crowds and donations. Mr. Poilievre railed against vaccine mandates, insisted the whole movement was not responsible for racist symbols or anti-government manifestos raised by some, and never called for the blockades to stop. A Poilievre sign hangs from a truck at the convoy protests in Ottawa on Feb. 16.Justin Tang/The Canadian Press His critics have labelled him a Canadian Donald Trump, and he has mirrored populist MAGA techniques. He built a social-media following bashing Liberal “elites,” played peek-a-boo with conspiracy theorists, and avoided contradicting those who insisted the World Economic Forum is secretly running Canada. At rallies, his culture-war calls to defund the CBC won the loudest cheers. But he is no Donald Trump in tenets or temperament. He doesn’t echo the anti-immigrant rhetoric, and abhors Mr. Trump’s gargantuan deficits. He is so calculated that he could never be the erratic bundle of impulses that rambles at a Trump rally. Away from cameras, there is another Pierre Poilievre: A quieter, private, wonky bookworm with a nerdy laugh who seems too affable to share a body with the political performer seen on YouTube demanding finance ministers give him yes-or-no answers. In his lifelong political education, he has learned to turn opposition into opportunity, to delight at progressives clutching pearls while he grabs attention, and to never back away from fights. His job now is converting those who feel they’ve been struggling to the message that big government is their burden. That’s the mission he’s been practising for his whole life. Mr. Poilievre and his wife, Anaida, stand up as he is declared the new Conservative leader in Ottawa on Sept. 10.Justin Tang/The Canadian Press Mr. Poilievre has repeated his origin story many times in recent weeks. He was born to a 16-year-old unwed mother whose mother had just died, and adopted by two schoolteachers who had come to Calgary from Saskatoon. In fact, when his birth mother had a second son, Donald and Marlene adopted Patrick too. His family’s heritage, Mr. Poilievre has said, is like Canada’s: “all mixed up.” The Calgary kid was named Pierre because of Don’s franco-Saskatchewan heritage. Don’s grandfather, Joseph, had emigrated from France in 1904 to what would become Prud’homme, northeast of Saskatoon. Don’s father Paul farmed, ran a garage in Leoville, a hotel in Moose Jaw and settled into real estate in Saskatoon. Marlene’s mother, Louise Schartner, had her daughter in rural Saskatchewan during the Depression, but separated from Marlene’s father only months later. His biological grandfather was an Irish immigrant from County Meath. Don and Marlene married in 1971 and were older parents, on either side of 40, by the time they adopted Pierre in 1979. Pierre’s parents were teachers through the rough recession of 1980s Alberta, and he described their standard of living, in the suburban southwest edge of Calgary on Shawnessy Drive, as modest. The boys could play hockey and go on camping trips. Pierre played sports and was on the wrestling team, until a teenage shoulder tendinitis forced him to stop. That injury opened a door. He was a bored teenager, he told The Globe and Mail in a 2015 interview. And as he watched his mother head to an Alberta Tory riding-association meeting, 14-year-old Pierre begged to tag along. He caught the bug. He threw himself into politics, and started reading books. A bust of economist Milton Friedman at the Stanford University campus in California.Paul Sakuma/The Associated Press While still a teen, he found the book he has for 20 years described as his seminal influence: Milton Friedman’s Capitalism and Freedom. The book is Mr. Friedman’s argument that economic freedom is key to personal freedom, and that apart from limited cases where government action is needed for a greater neighbourhood good, government initiatives infringe on personal freedom. Yet Mr. Poilievre’s biggest influence was surely participating in real-life politics, taking on adult roles as a teen. He went to meetings of both the Alberta Progressive Conservatives and federal Reform Party, knocked on doors in campaigns and served on a riding executive. A week after his 17th birthday, he was a delegate to Reform’s 1996 national convention in Vancouver. He did phone canvassing for a young Calgary Reformer running for the first time, future federal cabinet minister and Alberta Premier Jason Kenney. But something apart from a shoulder injury was happening as he threw himself into politics: His parents separated. In his mid-teens, Pierre was shuffling between Shawnessy Drive and his father’s new home. Eventually, Don came out as a gay man. In his Sept. 10 victory speech, Mr. Poilievre for the first time spoke of his father and his long-time partner’s relationship publicly as he acknowledged both of them in the audience. In the mid-1990s, there were still few openly gay politicians and celebrities, and coming out came with more social vulnerability. Shuvaloy Majumdar, a former Conservative staffer who met Mr. Poilievre when both were 18, said that among people Mr. Poilievre knew, his father’s sexuality was no secret. “I’ve never seen him uncomfortable with his family. It was never something he hid or pretended didn’t exist or lied about,” Mr. Majumdar said. “It was always, ‘This is who I am. This is where I come from.’” At the time, debates about issues such as pension benefits for same-sex partners, including in the Reform Party, with its wide vein of social conservatism, included homophobic warnings that such measures would promote homosexuality. “[Pierre] never thought the rights of sexual minorities was icky. He was never repulsed by those things. I think he was trying to understand the decisions his father was making for himself,” Mr. Majumdar said. Perhaps, he said, the dislocation of his parents separating encouraged him to find his identity in a political community. In 2005, as a rookie MP, he gave a speech opposing gay marriage, arguing civil unions would ensure equal rights while preserving the traditional definition of marriage. In typical Poilievre style, he blamed the Liberals. Atypically, he declared deep respect for those who disagreed with his stand. Fifteen years later, in 2020, he told La Presse that he’d learned a lot and realized gay marriage is “a success.” When erstwhile Conservative leadership candidate Richard Decarie called homosexuality a choice, Mr. Poilievre tweeted: “Being gay is NOT a choice. Being ignorant is.” Mr. Poilievre shakes hands at a barbecue during the Calgary Stampede this past July. He studied at the University of Calgary in the 1990s, where he got involved in conservative politics.Todd…