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Avi Lewis spent most of July in Quebec improving his French and knocking on doors.Roger LeMoyne/The Globe and Mail

When the Orange Wave crashed over Quebec in 2011, it famously left a high-water mark of 59 MPs in its wake – a remarkable and anomalous tally for the NDP.

That was 15 years ago. Today, with Alexandre Boulerice leaving federal politics and a by-election looming in his Montreal riding, the party has been left temporarily seatless in the province again, as it has been for most of its history.

Newly elected federal NDP Leader Avi Lewis is trying to stem that tide. He spent most of July in Quebec improving his French and knocking on doors, trying to solve the puzzle of New Democratic futility in what is arguably Canada’s most progressive political culture. In an interview with The Globe and Mail, he described the conundrum as “one of the enduring mysteries of Canadian politics.”

After all, the party and the province agree on many things, notably the importance of the environment and a strong social safety net. For decades, however, the NDP failed to break through in Quebec, and now appears to be sliding back into irrelevance east of Cornwall, Ont.

Making matters more personal for Mr. Lewis, his family traces its roots in Canada to Montreal. They went on to shape the NDP for most of its existence, starting with his grandfather David Lewis and then his father, Stephen Lewis, who died earlier this year. Neither of them made much of a mark in French Canada.

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“It is a mystery, and I hope I can unknot it,” the younger Mr. Lewis said. “I think this province is ready for another date with democratic socialism.”

“It may not be right away, because I think Quebeckers really need to feel that people have an understanding of Quebec in their skin, and not just in their head. I know I feel it, but I know I have a lot to learn.”

His work this summer began with three hours of French lessons every morning – a “luxury,” said Mr. Lewis, for someone with “high-school French from Ontario circa 1982.” He did quarrel over the validity of some Quebec political jargon with his teacher, who is, curiously, from France. The strain of language acquisition has made him painfully aware of “the descent of neuroplasticity as I approach the age of 60.” But his French has clearly improved since a leadership campaign that exposed the party’s heavy anglophone tilt.

The party leader has also been basking in Quebec culture, from the hit Crave drama Empathie (watching once with subtitles, once without) to a trip to the Plains of Abraham in Quebec City. The richness of the province’s cultural offerings left him with a rosier view of the state of French in Quebec than the political consensus within its borders that the language is threatened and declining.

“I think the ability of this province to produce art and music and film and culture and have an intellectual life at the level that it does, to me, is a persuasive argument that French is alive and well,” he said. “I have a lot of unabashed envy for the fact that protecting a language has meant maintaining cultural protections that have long since been dismantled in the rest of Canada.”

Language and identity have always given the NDP trouble in Quebec. David Lewis was raised in Montreal after immigrating from revolutionary Russia as a child, his politics honed in the working-class, left-wing, Jewish milieu of the city’s Plateau neighbourhood in the 1930s – far from the Québécois mainstream. When David was learning a new language in Canada, to complement his native Yiddish, it was the English of Dickens and the Protestant school system.

Later in life, as NDP leader in the 1970s, he could muster enough “political French” to get through radio interviews, his grandson recalled. But by then, the party was a cipher in Quebec, dominated by the alliance between Prairie populists and the union workers of Ontario.

When David was running the party, his Montreal roots didn’t count for much with voters. Said the NDP’s long-time Quebec stalwart Karl Bélanger: “David Lewis was not considered a Quebecker by Quebeckers.”

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His son, Stephen, was raised in Ontario and made his political career there. He led the provincial NDP to Official Opposition status at Queen’s Park soon after his father did the same in Ottawa. Avi, in turn, moved even further west, twice running for parliament in British Columbia, where he lives.

Speaking about Quebec’s most sensitive issues without alienating mainstream voters is a feat that has undone NDP leaders with a much stronger base in the province. Quebeckers’ aggressive stance on secularism can clash with the party’s embrace of multiculturalism, as Tom Mulcair learned on the cusp of an election victory in 2015, when he hurt his chances by defending the right of Muslim women to wear a niqab during citizenship ceremonies.

On issues such as Quebec’s popular Bill 21, which bans some public-sector workers from wearing religious symbols, the younger Mr. Lewis hopes he and Quebeckers can agree to disagree.

“I think there’s huge common ground and we just have to work with that, and just acknowledge the differences, not try to weasel-word around them or cover them over with some rhetoric,” he said. “We’re allowed to disagree in a democracy.”

Few people have more experience with the NDP’s long fight for relevance in Quebec than Mr. Bélanger, who became a party militant in the early 1990s before helping to engineer the Orange Wave under the charismatic leadership of Jack Layton. Mr. Bélanger fears that Mr. Lewis has a long way to go in rescuing the flotsam of 2011, let alone recreating that magic year.

The veteran operative and now radio host said he thought Mr. Lewis’s take on Bill 21 was “a little naive,” and worried that if the NDP doesn’t recover Mr. Boulerice’s seat, it could take decades to regain a beachhead in Quebec. He said he and Mr. Lewis haven’t spoken since the latter became leader.

“He’s starting from a distance, compared to where Layton was and especially compared to where Mulcair was,” Mr. Bélanger said.

Even natural voters for Mr. Lewis can’t help but agree. During a visit to the Montreal music venue La Sala Rossa, which used to be a Jewish community centre frequented by his grandfather, Mr. Lewis was greeted warmly by several young fans.

One of them, Palden Khe-Changsoo, said he always voted NDP and would continue to under Mr. Lewis. But, he added, “I’m worried about Quebec for him – his French isn’t good.”