"Canada isn't doing well right now because it's Albertans who control our community and socio-democratic agenda," he told Les Francs-Tireurs in 2010. "It doesn't work."
And he didn't stop there, adding, "Certainly when we look at the great prime ministers of the 20th Century, those that really stood the test of time, they were MPs from Quebec. This country — Canada — it belongs to us."
A day later, Trudeau apologized for the comments during a brief media scrum in Vancouver.
"I'm sorry I said what I said," The Globe and Mail reported him as saying Friday. "I'm here to serve."
But the Tele-Quebec interview couldn't have emerged at a worse time for the star Liberal candidate, who is actually trying to win friends in Alberta, as a key by-election in Calgary nears its conclusion.
The Liberals have a rare opportunity to gain a seat in Calgary-Centre, with candidate Harvey Locke threatening to capture what has been a bastion of Conservative power for the last 40 years.
A star contender for his party's leadership crown, Trudeau seems to be single-handedly transforming a battered Liberal party into a national contender again.
While a recent Nanos poll shows the Conservatives ahead with 34 per cent of popular support, the Liberals appeared to make astounding gains. They now trail the Tories by just five per cent and are in a dead heat with the NDP.
Trudeau's candidacy is widely seen as the reason for the Grits' much-improved fortunes, with his name even pushing Liberal support to 24 per cent or higher in the four western provinces — not a traditional bastion of Liberal support.
But the 2010 Alberta comments threaten to derail that momentum.
For its part, the Trudeau camp issued a statement on Facebook, laying blame, predictably, on the Tories.
"The Conservatives are using out-of-context statements made years ago in a long interview. They are clearly concerned that they are losing the by-election in Calgary Centre and are resorting to smear campaigns to stop their slide," the statement said.
“It was a very long interview in French," the statement said. "What he was saying was that Quebecers see a government that doesn’t share their values."
In a brief media scrum in Vancouver, Trudeau said the interview was focused on urging Quebec residents to stop voting for the Parti Quebecois. He also said that he spoke of Alberta but he should have clarified that he meant to say Conservative Prime Minister Stephen Harper.
But pundits and analysts were not buying it.
On CBC's At Issue on Thursday night, panellists essentially took turns extolling the damages to Trudeau's prime ministerial ambitions.
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Political analyst Bruce Anderson suggested Trudeau's comments were not only a serious setback to Liberal hopes in upcoming Alberta by-elections, but to Trudeau's aspirations to become a national leader.
Don't call it a mere gaffe, added columnist Chantal Hebert. "To me, that is a major error in judgement and it speaks to something you don't look for normally in a national leader."
During the segment, columnist Andrew Coyne was no less charitable.
"He gave no indication in the interview that he didn't actually believe what he was saying," he said. "If you're running for national office in a famously fractious country where your job is to be a unifier not a divider, this is the kind of thing that's certainly going to be a lot of marks against you."
Newspapers joined the chorus of condemnation. Matt Gurney of the National Post wasted no time in reminding readers why the Liberals were drummed out of power in the first place.
The Papineau, Quebec MP 's words, Gurney wrote, "reek of arrogance".
"This certainly won’t help the Liberals in Alberta, particularly in the upcoming Calgary Centre by-election," he added.
And in the Twitterverse, Trudeau's name was trending for all the wrong reasons on Wednesday.
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Trudeau's comments surfaced on the heels of another Liberal misstep, again involving Alberta.
This week, Ontario Liberal MP David McGuinty resigned as natural resources critic after suggesting Alberta MPs need to expand their energy policies to include the rest of Canada or "go home".
Any bad news for the surging Liberals, of course, is good news for the Tories, who piled on with all the expected enthusiasm.
Federal immigration minister Jason Kenney denounced the comments of both politicians as evidence of anti-Alberta bias within the Liberal party.
"This is the worst kind of divisiveness, the worst kind of arrogance of the Liberal party and it brings back, for many westerners, the kind of arrogance of the National Energy Program, which of course devastated the western economy," Kenney told the CBC.