Thomas Mulcair grew up in a Montreal suburb as the second-oldest of 10 children in his family, which is noteworthy enough. Even more remarkable, though, at least by today’s standards, is that he remembers his parents hoping for just a few more kids. “When my mother would have a child,” the NDP leader recalled recently, “my father would always bring her 14 roses, because they decided when they were married that they would have 14 children.” His father, Harry, was an insurance man of Irish-Catholic descent, and his mother, Jeanne, a teacher from an old French-Canadian family, was of course Catholic, too. For another public figure, details like these might be mere background colour. In Mulcair’s case, apart from the roses, every bit of it—the many brothers and sisters, the Quebec roots, a Catholicism devout enough to entail mass on weekdays before school, even the Irish streak—is central to his emergence as a formidable political fighter and plausible future prime minister.

By his own account in an interview with Maclean’s, backed up by the observations of some who have worked closely with him, Mulcair’s upbringing in such a large, tightly knit, complex household remains the template for his important relationships. Aides and allies say he maintains unusually close contact with family and old friends, cultivating an intensely personal network and leaning on time-tested loyalties more than most top politicians. While he is no longer an observant churchgoer, Mulcair’s brand of left-leaning politics flows directly out of his home province’s distinctive and deep well of progressive Catholicism—a powerful influence on seminal Quebec politicians of the past, including Pierre Trudeau. As for Mulcair’s Irishness, Graham Carpenter, an old family friend and long-time aide, alludes to his “Irish world view,” and not jokingly, as an explanation for Mulcair’s storied scrappiness and more. “There’s mystique to it,” Carpenter says, “that’s for sure.”

Bringing Mulcair’s defining qualities into sharper focus is a prime preoccupation on Parliament Hill as the fall political season begins. Following his convincing win last spring in the bitterly fought New Democratic Party leadership race, Mulcair’s first few months squaring off against Stephen Harper in the House erased any doubt that the Tories must view their new chief adversary with the utmost concern. Before he took over as NDP leader on March 24, the party had been either languishing in third place in the polls, or, at best, vying with the Liberals for second. But after Mulcair assumed control, they moved swiftly into rough parity with the Tories, and, starting with a few early summer polls, even a shade ahead—the first time the polling firms Ekos and Nanos ever put the NDP in first place in their national tracking of voter preferences.

That early flush of success was far from preordained. At the moment he won the NDP leadership, two troubling questions loomed over Mulcair. Wasn’t he bound to be a letdown compared to Jack Layton, whose spring 2011 election breakthrough—vaulting the NDP into second place for the first time ever, followed less than four months later by his death from cancer—elevated him to iconic stature? And, as a fresh leader of the official Opposition whose image was still unformed in the minds of most voters, wasn’t Mulcair liable to be defined—just as the last two hapless Liberal leaders, Stéphane Dion and Michael Ignatieff, had been—by derisive Tory attack ads?

As it turned out, Mulcair has rarely been measured against his beloved predecessor’s memory. Perhaps the contrast between Layton’s warm, outgoing populism and Mulcair’s dogged, self-contained pugnacity is just too glaring. As for those inevitable Tory attacks, Mulcair seemed to feed off them. In their first bid to portray him as a menace, Harper’s wrecking crew tried a variation on the theme they’d used to devastating effect on Ignatieff, casting Mulcair as an “opportunist” within minutes of his winning the NDP leadership. Mulcair says that line gave him the “biggest belly laugh” of that happy night. After all, he might have many flaws, but having arrived in Ottawa in 2007 as the rarest of political birds—the sole NDP MP from Quebec at the time—Mulcair couldn’t plausibly be accused of having sought an easy path. “I think they had to reset the dial,” he says. “I think they’re still trying to figure out what the target is with me.”

For anyone trying to figure out this would-be prime minister, the starting point has to be that sprawling family. He was born on Oct. 24, 1954, at Ottawa’s Civic Hospital, delivered by the same doctor, his mother was pleased to note thereafter, as Princess Margriet of the Netherlands about a decade earlier, when the Dutch royal family was taking sanctuary from the Nazis in the Canadian capital. In the mid-1950s, the Mulcairs lived across the Ottawa River in what was then Hull, Que. (later renamed Gatineau), but they moved to Montreal while Tommy was still a preschooler. They eventually settled into a five-bedroom house in the comfortable Chomedey neighbourhood, where there’s a large English-speaking community, including many Greek immigrants, within the predominantly French-speaking suburb of Laval.

The children kept on coming. Mulcair and his one older sibling, his sister Colleen, now a public-health nurse in Ottawa, often took responsibility for their younger brothers and sisters. “It was great. It was riotous,” Mulcair says. “I can remember my mom or dad saying, ‘Okay, Colleen, you take care of those two; Tom, you take care of those two,’ when it was bedtime.” His younger sister Deborah Mulcair says her brother did more than read bedtime stories. “He essentially raised his younger siblings,” she says. “He was quite attentive.” When they had a problem in school, for instance, she says it was often Tom who talked them through it. Indeed, when Deborah was unsure about whether to go on to university at all, it was her eldest brother, she says, whose encouragement persuaded her to go. She now teaches finance at Vancouver Island University in Nanaimo, B.C., and helped organize West Coast events in his NDP leadership run.

Mulcair was a stellar student and a tough athlete. Religion figured prominently in his upbringing. “As kids, we would often go to church before breakfast on weekdays,” he says. He eventually attended the local Catholic high school, playing basketball and defensive tackle on a local minor football team. (He still sprinkles his political chat with sports analogies.) But the more telling influence was that of the school chaplain, Father Alan Cox, who “inspired us all to get very much involved in social action.” Cox organized Saturday subway rides into Montreal’s poorer quarters to engage students in good works. “You know,” Mulcair says, “help an old person to move some stuff in a house, work the phones in a drop-in centre for people in crisis.” He’s still in touch with the priest, describing him as “a great adviser.”

Social responsibility instilled at school blended with political talk encouraged at home. His parents were staunch Liberals. In fact, Mulcair is directly descended on his mother’s side from Honoré Mercier, a founding figure of the party at the provincial level and Quebec’s ninth premier. Both his mother and father read widely and paid respectful attention when Tom, even at an early age, expressed views on politics. “It was one of those areas,” he says, “where you were allowed to be an adult.” As a direct result, he says, he decided on a career in politics when he was only 14 years old.

Through the 1960s, his father was first the regional manager for one insurance company, and then a vice-president of another. His eldest son says he was “a very strong character, very wilful, very determined.” But a change in corporate ownership put him out of a job in the early 1970s, prompting him to give up on the city grind. He came home one day declaring that he would never wear a tie to work again, and moved his family to Ste-Anne-des-Lacs, a bucolic town in the Laurentians less than an hour’s drive north of Montreal, where the family already had a cherished summer cottage on Lac Marois.

Harry set up shop as a small-town insurance broker. Jeanne had already gone back to teaching in Laval, despite still having young children at home, and went on to teach French for many years near Ste-Anne-des-Lacs at a school for juvenile offenders and other troubled youth. Now 80, she lives in retirement in the area, where her children, including Tom, still retreat for summer breaks. Harry Mulcair died in 1994, a few months before his eldest son’s first election win.

By the time the Mulcairs were re-establishing themselves on the lake, Tom was already studying law—at a precociously early age. In Quebec, university-bound students complete a two-year college program after high school. Mulcair attended Vanier College, where he says he was “very, very active” in student politics. He was among the leaders of a student strike, which ended, he says with characteristic bluster, when the administration “had to meet all of our demands and come crawling back.” Activism didn’t hurt his grades: he was accepted directly out of Vanier into McGill University’s prestigious law school in 1973 at 18, a rarity. “The first year was quite daunting,” he says. “The reading was monumental.”

He more than held his own among classmates who were typically a few years older, with B.A.s or sometimes M.A.s under their belts. To this day, Mulcair’s formidable intellect and ability to quickly master large volumes of written material is often cited by those who work with him on policy files. He did more than hit the books at law school, though, becoming president of its undergraduate students’ association. But Mulcair is less than glowingly nostalgic when he reflects on his McGill years. “The faculty wasn’t very open,” he says. “There was still a 1940s wall between faculty and students.” And for the former Catholic-school social-causes volunteer, McGill’s establishment aura wasn’t entirely congenial. “I wouldn’t have back then, and I still wouldn’t today, describe McGill as progressive,” he says. There were exceptions. The venerable Frank Scott—constitutional law expert, poet, and long-time stalwart of Canadian socialism—gave a guest lecture series that thrilled him. “It was really quite something,” Mulcair says. In contrast to a faculty he often found closed off from the political and social concerns of students, Mulcair says the grand old man was “all openness.”

Yet Scott, a founding figure in the NDP and its predecessor, the Co-operative Commonwealth Federation, didn’t quite draw Mulcair into his partisan fold. Julius Grey, a Montreal lawyer who has known Mulcair well since the late 1970s, sees his friend as an example of Quebec’s distinctive sub-species of Catholic “centre-left progressive.” Many in the CCF and then the NDP were inspired, like Grey himself, by socialist ideas close to those at the heart of the British Labour Party. But in Quebec, Grey says, Catholic progressives—like Trudeau, his friend Gérard Pelletier, the journalist and politician, and Claude Ryan, whom Mulcair would come to revere—blazed another trail. They were a varied group, but a common denominator was the influence of “personalism,” a French intellectual movement that spread among liberal Catholics in the middle of the last century. It emphasized individual responsibilty—rather than, say, class conflict—as the moral underpinning for Catholics seeking reforms such as greater economic equality.

With his religious upbringing and formative high school experiences, Mulcair naturally leaned toward this progressive stream. He bonded with others of the same bent at McGill. Among them was his law school pal Steve Foster, who went on to become an Ontario judge before resigning from the bench in 2011 to work on Mulcair’s leadership campaign, and then join his staff as a policy adviser. Mulcair says Foster is “a guy out of the Catholic left, and a lot of the people he brought on board are out of the Catholic left.” In fact, Foster’s network was extensive enough to give Mulcair a ready-made support base in Toronto, where his leadership rivals had expected the Quebec-rooted candidate to be weak. “That was really stealth,” Mulcair says with palpable satisfaction. “They didn’t see that one coming.”

If tapping old relationships can stand Mulcair in good stead, the degree to which he’s steeped in a political culture that can at times seem almost quarantined could prove a liability. Indeed, one of his top aides, asking not to be quoted by name, describes the way Mulcair has internalized Quebec’s unique political style and preoccupations as both his undergirding strength and a limitation he must overcome. “He’s got to develop instincts on the ROC,” the official said, meaning “rest of Canada.”

Unlike most Montreal anglophones of his era, Mulcair was drawn straight to Quebec City when he graduated from McGill in 1977. With his adolescent political ambitions still burning, no law firm could match the lure of a junior post in the provincial justice ministry. Still, his entry into the bureaucracy was far from easy. Although Mulcair could speak French reasonably well, English was used most often at home when he was growing up, and his entire education was in English—typical, as he points out, for kids from mixed English-French households when he was young. In his first job, he would have to draft formal legal documents, and converse with accomplished lawyer colleagues, all in French. “I was way behind,” he says. “It was a huge effort to bring my French up to snuff.”

Fortunately, he had a tutor at home who’d been raised in Paris. In 1976, Mulcair had married Catherine Pinhas when they were both just 21. They had met two years earlier when she was visiting Quebec from France for a cousin’s wedding at Ste-Anne-des-Lacs. As he struggled to make his way in the Quebec civil service, his young wife corrected his French in the evenings. Although Pinhas went on to her own career as a psychologist in Montreal, friends say she remained a constant, steadying factor in his professional life. During his interview with Maclean’s, she sat by him in the booth of a diner, near their modest home just west of Montreal in Beaconsfield. While far from intrusive, she laid a cautionary hand on his sleeve at one point, when he seemed on the verge of turning argumentative, after his second double espresso, in answering a critical question about his possible shortcomings as an orator. (He conceded none.)

Mastering French with her help was, he says, “a huge turning point in my life.” But that didn’t erase his McGill-educated, mostly English-speaking background—and certainly didn’t make him a separatist. So, in the emotionally charged days of then-premier René Lévesque’s 1980 referendum bid to take Quebec out of Canada, he stood out as a rare supporter of the federalist No side within the justice ministry. “It was so openly pro-Yes within the department itself,” Mulcair says. “Sometimes the words would get a little harsh. I remember one guy, another lawyer, sitting me down to have lunch and literally haranguing me for the whole time, just saying, ‘How can you possibly vote against Quebec?’ And I’d say, ‘Well, I’m not voting against something, I’m voting to keep something, which is our attachment to Canada.’ ”

The referendum is often dramatized as a mano-a-mano bout between Lévesque and Trudeau, with the country’s future hanging in the balance. But Mulcair conjures up a vivid memory of another key combatant for the federalists, Claude Ryan, then the provincial Liberal leader, former editor of Montreal’s influential Le Devoir—and one of those progressive Québécois Catholics. The scene is a hall in Val-Bélair, very near Quebec City. “The guy’s voice is cracking. Four thousand people in a packed, packed hall. Hot,” Mulcair says. “I just remember the drive and determination.” Ryan would become Mulcair’s most influential mentor.

After the No side’s historic referendum win, Mulcair worked for a few years as the only anglophone bureaucrat on staff at the Conseil de la Langue Francaise, the politically sensitive body that oversees Quebec’s controversial language laws. That experience was invaluable when he moved back to Montreal in 1983 as director of legal affairs for the English-language rights group Alliance Quebec. As Mulcair was immersing himself in Quebec’s fraught language politics, Ryan lost the 1981 provincial election, and was replaced as provincial Liberal leader by Robert Bourassa, who in turn made Ryan his education critic. Since schooling was a hot-button issue in the language wars, Ryan and Mulcair found themselves entangled in the same files.

After Bourassa’s Liberals returned to power in 1985, Ryan became education minister and pulled Mulcair more tightly into his circle. He named him to help grapple with a thorny issue, involving illegal English Catholic schools set up in defiance of the language laws. Mulcair helped craft a compromise that allowed the outlaw schools to keep operating, while imposing stiff fines to stop new ones from being created. “This is the Claude Ryan method: put all the best people around the table and really hammer it out,” he says of the way they settled the matter, adding: “You’d better come prepared to a meeting with Ryan.” Next, Mulcair was appointed head of a provincial regulatory body that oversees professions. He made headlines in Quebec by confronting the formidable doctors’ organization over what he saw as its failure to discipline physicians for sexual misconduct.

During these years, he credits Ryan with instilling in him the values of “rigorous public administration” and the “enforcement of regulation,” especially against powerful interests. “Ryan was very tough; he was very Irish in that way,” Mulcair says. “But he also had a good Catholic streak in him; he was always devoted to social causes.”

In Quebec’s 1994 election, Mulcair made his long-planned jump into politics as a Liberal. Although the Parti Québécois beat the Liberals badly, he managed to win the Chomedey riding on his old Laval home turf. The aging Ryan continued to advise him, but Mulcair soon gained a reputation as a hard-driving opposition fighter in Quebec’s national assembly that didn’t bear much outward resemblance to his mentor’s exacting and often aloof image.

Mulcair’s run as an enforcer for Jean Charest’s Liberals reached its apogee in 2002, when his relentless attacks helped force a Parti Québécois minister’s resignation for alleged influence peddling. Soon after, Mulcair was making similar claims against a PQ lawyer, when they crossed paths in a TV studio. Mulcair snarled off-air, “I’m looking forward to seeing you in prison,” and added, for emphasis, an unprintable French insult. He later lost a defamation suit related to that clash. But when Charest took power the next year, he named his elbows-up lieutenant to the post he most coveted, environment minister, and also made him deputy premier.

Mulcair says he and Charest worked well together for a time, but their relationship soured. The rift was partly about ideology. In Quebec, the main partisan dividing line is between federalists and separatists. That made the provincial Liberal party home for federalists across a sometimes uncomfortably wide ideological band. Charest, a former federal Conservative leader, governed from well to Mulcair’s right. As premier, he tried to reduce the clout of Quebec’s unions, for instance—one of several steps that angered the province’s left. Charest faced protests on the streets.

From retirement and in failing health, Ryan voiced misgivings to his protege in a final phone conversation. “I remember his words well: ‘The way things are going doesn’t respect Liberalism in terms of social responsibility,’ ” Mulcair says. “He was sending a clear message to me as one of his close acolytes in the new government that he thought it was drifting too far right.”

Ryan died on Feb. 9, 2004, at 79. Two years later, Mulcair quit Charest’s cabinet rather than accept a demotion to minister of government services. As environment minister, Mulcair says he “bumped heads” with Charest more than once. Their differences turned irreconcilable when Mulcair refused to sign over land in a provincial park to a condo developer. At the precise moment when Mulcair had to decide whether to swallow Charest’s offer of a lesser role or quit, he stood in an antechamber outside Charest’s office in Quebec City’s landmark 1920s-era Édifice Honoré-Mercier, and phoned his wife and their two adult sons—one now a sergeant in the Quebec provincial police force, the other a science teacher at a Montreal college. All three agreed he shouldn’t bend and settle for a role that he saw as “sort of a joke.”

His dramatic exit made Mulcair a valuable free agent. He was approached, he says, by federal Liberals, Tories and New Democrats—though not by the Bloc. Pierre Ducasse, Layton’s key Quebec adviser, was the NDP’s emissary. Ducasse had been an architect of the party’s so-called Sherbrooke Declaration, which controversially asserts, among other things, that Quebec’s national assembly has the right to set the sovereignty question in any future referendum, and that a bare majority—50 per cent plus one—would be enough for Quebec to leave Confederation. That contradicts the Supreme Court of Canada’s key 1998 reference decision, which says any referendum question and the vote’s result would have to be deemed clear by the Parliament of Canada to trigger succession negotiations.

It was Layton’s bid to make the NDP an attractive new option for Quebec’s soft-nationalist francophones, and happened also to enhance the party’s appeal for Mulcair. Although he had been, along with Grey, a prominent defender of English language rights, he accepted the Quebec government’s efforts to promote French, and was enthusiastic about an assertively distinctive, left-of-centre Québécois political culture. Now Layton pursued Mulcair with the message that he saw Quebec much the same way, even if his NDP had barely a toehold in the province’s politics. Layton and his wife, Toronto MP Olivia Chow, dined one night with Mulcair and Pinhas at the country-style Mon Village restaurant near Layton’s hometown, Hudson, Que. “I guess it was about a six-month process,” Mulcair says of the courtship. “Sometimes I sat back and thought maybe I should hang up my skates, and get a decent-paying job in an area that I like, maybe just do that for a few years.”

But that didn’t look like a serious possibility. In the fall of 2006, Mulcair strategically accepted an invitation to speak at a federal NDP convention in Quebec City. As Charest’s environment minister, he had passed a European-inspired Sustainable Development Act, lending him added star appeal among green-tinted New Democrats. Quebec’s French-language media took notice, and incredulous talk spread that Mulcair might join a party that didn’t hold a single seat in the province. “Good friends were openly laughing,” he says. After all, the NDP had drawn a dismal 7.5 per cent of Quebec’s popular vote in the 2006 federal election.

Layton persuaded Mulcair that all that could change. “A lot of people had seen the NDP as a nudge party, kind of pushing the other guys in the right direction,” Mulcair says. “But Jack had every intention of bringing us up to governing status.” Mulcair took the leap, and ran for the NDP in a by-election in Montreal’s Outremont, a long-time Liberal stronghold, in the summer of 2007. In the previous year’s election, the NDP’s candidate had taken 17 per cent of the vote in the riding. Mulcair won it resoundingly with 48 per cent.

Still, behind the scenes, Mulcair’s integration into the NDP as its new Quebec star was far from frictionless. Although Layton was born and raised near Montreal, he had forged his political career in Toronto, and his key aides were from Ontario and points west. Mulcair soon lost patience over their approach on his home turf. “One of the things I had to make them understand in Ottawa,” he says, “is that they could no longer run a unilingual English shop and then have some stuff translated into crappy French.” He complained directly to Layton during the by-election about wooden French in NDP pamphlets.

But it wasn’t just a matter of poor translations. Mulcair also objected to what struck him as hackneyed leftist messages. “It was this 1950s boilerplate,” he says, “which is already bad enough, stilted enough, in English, but it was being translated into even worse French.” And Mulcair found the NDP’s emphasis on expanding entitlements like government-funded daycare and prescription drugs problematic—since Quebec already offered these benefits as provincial programs. “That’s why we pay pretty high taxes,” he says he told Layton. “If you start promising a whole series of new social programs to Quebecers who are already paying for the ones they’ve got, they’re not going to get it.”

Not surprisingly, Mulcair’s acid, early judgments rankled some NDPers who had been toiling for the cause long before he joined. He derided some of them for aiming too low, content with incremental growth in their share of the vote. He even sparred occasionally with veteran NDP MPs, going public, for instance, with blunt criticism of B.C.’s Libby Davies over anti-Israel comments she made at a demonstration. Much later, during the leadership campaign, stored-up resentment over Mulcair’s penchant for finding fault emerged in the form of persistent complaints from within the party apparatus that he was hard to work with.

In the 2008 election, though, Mulcair remained the only NDP winner in Quebec. Returning to Ottawa, he kept living up to advance billing as a tough customer in question period. And, as Layton’s Quebec lieutenant, he gave the NDP its first marquee player in the French-language media. For all that, nobody saw the 2011 election result in Quebec coming. Layton’s personal appeal soared across Canada early that year after he bounced back from his first bout with cancer. His campaign that spring, cane in hand as he recovered from a broken hip, was extraordinarily compelling—especially, it turned out, among Quebec voters. The NDP won a staggering 59 seats in the province as a result.

Or, at least, the bon Jack phenomenon was widely credited. For his part, Mulcair tends to put the emphasis on organizational work he oversaw in the years and months before the election-day breakthrough. Asked to explain what came to be called the “Orange Wave,” he says: “A lot of hard work on the ground. There were not a lot of people in Ottawa who understood that if we wanted to go beyond having the symbolic presence of one guy who was able to get elected in Outremont—if we wanted to make it real—we were going to have to get some resources and we needed some people.”

Layton’s death late last summer, after a brief, second battle with cancer, released a national outpouring of grief. Mourning had hardly subsided when leadership speculation inside the NDP began in earnest. First out of the gates last fall was Brian Topp, who had been Layton’s campaign director. Topp boasted establishment NDP endorsements and the backing of key elements of Layton’s machine. Mulcair started much more slowly, but by early 2012 he had overtaken Topp—and he never looked back. He campaigned tirelessly, holding events every single day, including over the Christmas period, and sleeping just four hours a night.

Raoul Gebert, formerly president of the NDP’s Quebec wing, came aboard as campaign director. Gebert ran a patient, disciplined race, showcasing what he calls Mulcair’s “skill set”—polished, fluently bilingual, unflappable debating and confident media presence—rather than emphasizing policy or ideology. It worked almost flawlessly. Even an unusually nasty, last-ditch bid to stop Mulcair backfired. Ed Broadbent, the former NDP leader and Topp’s most prestigious endorser, went public in the campaign’s final days to slam Mulcair as temperamentally too divisive to lead.

If anything, being attacked by an elder statesman seemed to earn Mulcair sympathy. It wasn’t just Broadbent lashing out. Some of Mulcair’s rivals picked up on his readiness to criticize the NDP from within as evidence that he wasn’t quite one of the tribe. “How can you inspire people to vote for our party,” asked Ottawa MP and leadership aspirant Paul Dewar, “when you don’t seem to be inspired by our party?”

Gebert makes no grand claims about Mulcair having overcome those reservations to win the hearts of the NDP rank-and-file. He emphasizes instead the party’s clear-eyed decision to pick the leader who looked most capable of consolidating and building on Layton’s 2011 gains. “It’s a very mature choice,” he says, “The party knows where it wants to go and knows that Tom is the person who can bring us there.”

Some politicians feed on the love of the crowd, or at least the fervour of the party faithful, and learn to stoke those passions. That doesn’t seem to be Mulcair’s way. Even his victory speech after he triumphed at the NDP convention in Toronto was oddly flat, laced with dispiriting stats on low youth voter turnout. Perhaps he’s sustained less by public adulation than by private feedback from trusted aides, family and friends.

For Mulcair, those groups tend to overlap. Graham Carpenter, for instance, who manages his Montreal riding office, is a lifelong family friend—the Carpenters, like the Mulcairs, have summer a place on Lac Marois. Carpenter had studied philosophy and was making a living tearing down old barns and recycling the wood when Mulcair, back in his early days as a Quebec cabinet minister, recruited him as a staffer. “I’ve heard him say he learned this trick from Claude Ryan,” Carpenter says. “In politics you find smart people you know, and everything else they learn on the job.”

Gebert says he hadn’t worked intimately with Mulcair before the leadership campaign, and soon came to realize there was no quick way to break into “the very tight-knit group who had worked with him for years and years.” Asked why some NDP insiders find their new leader hard to warm up to, Gebert suggests that Mulcair’s pronounced preference for long-term relationships over new allegiances is part of the explanation. “It’s very much a family affair, a loyalty affair,” he says, adding that Mulcair’s reliance on long-standing friends and advisers goes “beyond what I’ve seen elsewhere in politics.”

Carpenter suggests Mulcair’s staunch commitment to anyone who’s stuck with him is the flip side of his determination to crush opponents. “If he’s your friend, he’s the best friend you ever had,” he says. “And if he’s your enemy, you don’t sleep well.”

If that’s so, then restless nights might be in store for Harper’s strategists. Their first sustained frontal assault on Mulcair, launched May 17 in the House, didn’t seem to phase him. That day in question period, with no particular prompting, Heritage Minister James Moore, Harper’s B.C. lieutenant, accused the NDP leader of attacking “all of the West.” His grounds? Mulcair subscribes to the so-called “Dutch disease” theory that high oil prices push up the value of the loonie, making Canada’s manufactured exports more expensive abroad. It’s a widely held notion, though economists debate the extent of the damage to exports. Such nuances, however, aren’t QP fodder. “He should be ashamed of himself,” Moore thundered.

In a similar situation, Dion, the former professor, might have given a disdainful, detailed reply that wouldn’t have provided a TV sound bite. Ignatieff, the proud public intellectual, might have raised his eyebrows and tried to remain above the fray. Mulcair, politician since puberty, plunged into the fray. “Their priority is the unbridled development of the oil sands,” he countered. “We stand for sustainable development.” He argued that properly enforcing environmental rules would boost the cost of developing Alberta’s oil sands, thus easing oil-fuelled upward pressure on the Canadian dollar and helping manufacturers sell abroad. Tactics, temperament and training blended in his gut reaction. Ryan had taught him that “rigorous public administration” meant applying regulations fearlessly. And then there’s that fighting instinct, the Irish thing. He boasts of besting Moore that day in the House. “The guy blanched,” Mulcair says. “You’re supposed to back down when they’ve screamed at you.”

If Mulcair showed he can counterpunch when cornered, he’s not by habit an improviser. He prepares doggedly, working dark-to-dark shifts. Up most days by 5 a.m., he takes a run nearly every morning, then puts in a couple of hours at his desk at home before heading to his office around 8 a.m. He typically returns at 9 p.m. or later. Yet he’s selective about how he invests all that time. “His general preference is to do things well,” Gebert says, “and do one or two things less, rather than do every little thing.” Family matters, however, can divert him. On a B.C. swing during his leadership campaign, for example, he found out his mother was scheduled for a routine medical appointment. “We actually shifted the time of one event, and cancelled something else, so he could fly home in time to take our mother to the doctor,” Deborah Mulcair says.

Those who’ve seen it up close often find his attentiveness touching. Others who have been on the receiving end of a Mulcair critique are likely to find his manner cutting. It’s too early to predict how these counterpoised traits might combine—as Canadians gradually get to know him—into a more fully rounded public persona. What’s becoming clear already, though, is that this tough politician—his roots so deep and complex—might just have what it takes to withstand Stephen Harper’s efforts to tear him down long enough to make theirs the sort of rivalry that could define a political era.