CALGARY -- Liberal Leader Justin Trudeau has been spending time sparring in boxing gyms and holed up with policy advisers as he prepares for one of the tougher bouts of his career -- tonight's crucial leader's debate on the economy.
He comes into the debate somewhat on the ropes, refusing to release a full costing of his platform and sticking by his plan to run three consecutive deficits after the government posted a $1.9-billion surplus.
Observers say he arguably has the most to prove on the economic file, where he is perceived by many -- with the help of Conservative attack ads -- as a "lightweight."
While his campaign says the economy is at the heart of Trudeau's platform, others say the Liberal leader will have to work hard to show some gravitas on the file and not sound like a high-school drama teacher reciting lines.
"His challenge is to get Canadians to actually take him seriously," said Melanee Thomas, assistant political science professor with the University of Calgary.
"Justin Trudeau tends to lapse into high-school drama teacher a little too often. He's seen to be a lightweight."
Trudeau was in a good position until this week when the Department of Finance released figures showing the government posted a $1.9 billion surplus in the 2014-15 fiscal year, she said.
The surplus undermines the key element separating Trudeau from his opponents -- his plan is to run three years of deficits to pay for infrastructure initiatives and other promises while the others promise to balance the books.
"It means his messaging doesn't make sense," Thomas said.
With polls showing all three mainstream parties in a virtual dead heat, a lot is riding on the debate.
Royce Koop, a political science professor at the University of Manitoba, said debates often don't have much impact on an election campaign. But occasionally, when they do, they can turn everything on its head, he said.
"If any one of them gets a knock-out blow, that will change things."
Trudeau is likely to be more of a target this time around, he added. When the leaders last faced off, the Liberals were trailing third. Now, Koop said, it's a different story.
"Justin is more of a threat now so it's going to be a harder debate for him," he said. "They are going to pursue him more than the last debate."
Trudeau isn't fazed, his aides say. He's been boxing regularly to physically and mentally prepare for the showdown, as well as preparing with advisers. Trudeau was up with the dawn Thursday morning, paddling a canoe on his own down a stretch of Calgary's Bow River.
"Perfect day," Trudeau said to a small pool of photographers and TV cameras as the current took him toward the sunrise.
Trudeau will focus on the fact that what the Conservatives call prosperity has not trickled down to "the middle class and those working hard to join in," said one Liberal official.
"People don't feel very good about the economy."
Trudeau will echo his stump speech, arguing Prime Minister Stephen Harper has only posted a surplus by cutting funding to those who need it and criticizing NDP Leader Tom Mulcair's "irresponsible" promise to balance the books at any cost.
He's sticking with his plan to run deficits because the party thinks people believe it's necessary to invest in the country's future, the Liberals say,likening it to taking out a mortgage to buy a house.
"He was honest with people," said the official. "You're not stupid, we don't need to treat you like fools."