With the race to find Jack Layton's successor coming to a crescendo this weekend, three of the Mulcair's rivals — Peggy Nash, Nathan Cullen and Paul Dewar —dismissed the notion that the Montreal MP is the only candidate who can hang onto the party's historic gains in Quebec.
They were responding to consumer advocate and onetime NDP MP Phil Edmonston's assertion this week that it would be an "overwhelming insult" to Quebecers should anyone but Mulcair take the party's reins — a view widely shared by pundits in the province.
The Mulcair camp, meanwhile, touted a new CROP poll that underscored Edmonston's assertion.
The poll suggests Mulcair is by far Quebecers' preferred choice for NDP leader, with Brian Topp a distant second and all other contenders barely registering. Topp is a fluently bilingual native Quebecer but the veteran backroom strategist has nowhere near as high a profile in the province as Mulcair, a former provincial Liberal cabinet minister.
However, rivals insisted a Mulcair victory is not essential to the party's hopes of hanging onto the historic 59 seats the NDP captured in Quebec last May, vaulting it into official Opposition status for the first time.
"I just don't buy it," dark horse contender Cullen, a British Columbia MP, said in an interview.
"It would be like saying British Columbians won't vote for anyone but me."
Cullen said Quebecers want a leader who understands and is open to their aspirations; "it's not just your postal code" that matters.
Pundits in Quebec have virtually unanimously adopted Edmonston's line of reasoning but Cullen noted those same pundits predicted the NDP wouldn't win more than three seat in the province in the last election.
Dewar said Edmonston's sentiment is far from unanimous among New Democrats.
"We're a big party and there's over 130,000 opinions out there, and Phil's is one of them," the Ottawa MP told reporters at Toronto's convention centre.
Dewar, whose laboured French has hurt his chances, insisted he's still in it to win. He said endorsements from francophone colleagues, such as MP Helene Laverdiere, prove he's got what it takes to "connect with voters across the country."
Nash pointed out that Layton, whose personal popularity was huge part of the NDP's breakthrough in Quebec, was also initially written off in the province.
"Jack may have been born in Quebec but he was a Toronto MP and, while his French improved, when he started out as leader his French was not that strong," she said in an interview.
"I think you should build relationships with people and that's important. It's a desire and a willingness to reach out and build bridges, that's what we're all about."
Nash added that New Democrats don't like "being given ultimatums."
"I think people do have a choice. People are free to make up their minds as to who they want to support."
There are signs that many New Democrats may be struggling with whom to support. By Thursday morning, 47,000 of the 131,000 eligible NDP members had voted in advance, using preferential mail-in or online ballots. Advance voting continues until 11 a.m. ET Friday.
Assuming a relatively high voter turnout of 70 per cent, that means about half the ballots had already been cast by Thursday morning. NDP officials had been expecting the vast majority would vote in advance.
"I'm a little surprised the advance voting wasn't higher. I don't know what that means," said Nash.
Both Nash and Cullen said they've heard anecdotally from many New Democrats who are firmly decided about their first and even second choices but are torn over how to rank their preferences for other candidates. Such folks may be waiting to vote in real time on Saturday, when they can see how each candidate ranks on the first ballot and vote strategically on subsequent ballots to produce their preferred outcome.
"People are just solidifying their instincts," said Cullen. "It reminds me that there's no clear winner. There's no obvious runaway candidate."
After a long, slow start, the marathon contest has become polarized in the final couple of weeks as Topp and Mulcair and their supporters take pointed shots at one another. Edmonston's intervention on Mulcair's behalf follows a controversial broadside from former party leader and Topp supporter Ed Broadbent last week, in which he questioned Mulcair's temperamental suitability to lead and his alleged intention to cast the left-wing party in a more centrist mould.
Both Cullen and Nash are hoping the polarization will persuade New Democrats of the need for a compromise leader who can come up the middle and unify the party.
"I think what our members want is a positive campaign and for the party to be united and to come out of this convention even stronger," said Nash.
"My campaign has been about my ability to bring people together and that is a skill that I have."
Cullen said party unity is more on New Democrats' minds than it was 30 days ago.
"The attacks on Tom, the attacks on Brian shifted the tone of the whole debate," he said.
Cullen, who's been lauded for his sunny disposition throughout the race, said he didn't set out to position himself as a unifying alternative to the two perceived front-runners.
"It wasn't like, oh yeah, these guys are going to get angry so let's be strategic and never get angry. I'm just not an angry guy. I like the people in the race and I'm not going to pretend that I don't just to score some points," he said.
"So how does it help? I don't know."
Fear that the party's Quebec surge is already ebbing away has helped propel Mulcair into the lead in the dying days of the race, which will be decided by Saturday's voting.
But the NDP's complicated process for selecting a leader to replace Layton, who died last August after a battle with cancer, makes it difficult to handicap the outcome.
In addition to the advance voting by preferential ballot, an unknown number of additional online voters, as well as the roughly 3,000 who've registered to attend the convention, will vote ballot by ballot in real time, starting Friday night and continuing Saturday.