OTTAWA -- Justin Trudeau says the values imbued by his famous father guided him to enter politics and take the plunge into the Liberal leadership contest.

But as he prepares to take the tattered reins of the self-styled natural governing party his father once led, it's his maternal grandfather, Jimmy Sinclair, he's looking to for inspiration.

Pierre Trudeau's advice has been "at the back of my mind all my life," the leadership front-runner told The Canadian Press recently, "which is to do right by the opportunities that I have and to trust Canadians as a base proposition."

"But on the actual mechanical challenge that is facing me, I don't know that he'd have a lot of advice for me. The one thing he never had to do in his politics in his life was worry too much about the state of the Liberal Party of Canada. It was a big red machine that he took for granted."

If as expected, Justin Trudeau wins the leadership on Sunday, he won't have the luxury of ignoring the state of the party, which has been in a downward spiral for a decade. Liberals are looking to him as their best -- and perhaps last -- hope for survival after hitting an ignominious third-place low in the 2011 election.

The big red machine of his father's day is now a little red wagon with wobbly wheels, confined largely to Toronto and a few outposts in Montreal, Vancouver and Atlantic Canada. In huge swaths of the country, there is no semblance of a machine left, particularly in Quebec, his father's erstwhile bastion.

The scramble to turn almost 300,000 supporters into registered voters in the leadership contest served to expose deficiencies in the party's data base -- the lifeblood of any modern political organization -- and its woefully dated technological capabilities. In the end, less than half of those supporters registered to vote, despite being given an extra week in which to do so.

As one of Trudeau's strategists puts it, the exercise underscored the challenge facing the new leader: how to turn a "19th Century club into a 21st Century" political machine.

Faced with the daunting prospect of rebuilding -- or in many places, building from scratch -- Trudeau said: "I draw a lot more on my grandfather, Jimmy Sinclair, who was a good party man and who understood the need for an organization to connect and inspire and involve Canadians.

"For me, that's the centre of my challenge right now and, you know, for everything my father was able to achieve in the past, he didn't ever have to rebuild the Liberal party."

Sinclair was elected five time as a Liberal MP from Vancouver, from 1940 until his defeat in 1958, and served as fisheries minister under Prime Minister Louis St. Laurent.

According to Trudeau's aunt, Janet Sinclair, the 41-year-old Montreal MP's personality is closer to that of his grandfather than that of his enigmatic, cerebral father. In an e-book on Trudeau by Huffington Post's Ottawa bureau chief, Althia Raj, Sinclair said Trudeau is "outgoing, approachable, likeable and remembers names" -- much like her dad.

There's no denying Trudeau's people skills -- combined with his youthful good looks, great hair, political pedigree, optimism and energy -- have created a buzz that has helped lift the punch-drunk Liberals off the mat. Just the prospect of Trudeau as Liberal leader has boosted the party back into contention in public opinion polls, where the Grits have pulled even or slightly ahead of the ruling Conservatives while the NDP has sunk back to its traditional third-place slot.

But those heady -- and possibly fleeting -- poll numbers present another challenge for Trudeau: how to manage expectations.

It's a difficult task for any political leader and it's trickier than usual for Trudeau, who faces a curious mix of expectations: high, because he's his father's son, and low, because he's not his father.

Throughout the leadership contest, Trudeau managed to defy the naysayers -- including some of his leadership rivals -- who predicted his celebrity-driven popularity would evaporate once his lack of experience, depth and gravitas became apparent.

"Everybody said he's going to make mistakes and fall on his face. Guess what? He didn't," said New Brunswick MP Dominic LeBlanc, a lifelong friend.

"Those that thought the enthusiasm and the crowds and the attention would be short lived were wrong. It was long-lasting and I think it augurs well for the next two years leading up to the election."

He predicts the same discipline, hard work and under-estimated intelligence that became evident during the leadership race will see Trudeau through the next phase of his political evolution, from greenhorn leader to prime minister-in-waiting.

That said, LeBlanc believes it's unrealistic to expect Trudeau can keep people pumped and excited until the 2015 election. The task is more pedestrian, in his view: to keep the thousands of supporters amassed during the leadership contest engaged and transform them over the next two years into a disciplined campaign machine.

"We haven't had a network in a generation. So the challenge is how do you manage that goodwill and turn it into an (election-ready) organization."

Trudeau's most immediate challenge will come Monday, when he rises in the House of Commons for the first time as Liberal leader to joust with Prime Minister Stephen Harper in question period.

For the past two years, interim leader Bob Rae's deft performance has almost single-handedly kept the party in the parliamentary game. Trudeau -- who has held only minor shadow cabinet posts since he was first elected in 2008 and has admitted parliamentary theatre is not his forte --is bound to pale by comparison.

That's an inevitable consequence of opting for a fresh start with a young leader, argues LeBlanc, who predicts Trudeau will quickly adapt to his new role.

"Rae is a master parliamentarian with three decades of experience ... You can't choose renewal and generational shift and find the guy who's a master of his game with 35 years experience."

Until Parliament breaks for the summer in late June, the tentative plan is to have Trudeau meet the challenge head on, spending considerable time in the Commons, honing his fencing skills and growing more comfortable in his new starring role.

His schedule will be rebalanced when Parliament resumes in the fall, so that he can spend more time on the road doing what he does best: thrilling adoring crowds, raising money, motivating Liberal troops, building a campaign machine and recruiting potential candidates.

For his part, Trudeau said he's "deeply frustrated" by Harper's iron-fisted approach to Parliament, which he maintained has rendered the Commons "much less significant than ever before." He sees his challenge as making what goes on in the parliamentary sandbox relevant to the real concerns of Canadians.

"That's going to require that, yes, I perform well in the House but also that I stay very much outside the Ottawa bubble connecting with Canadians across the country."

Trudeau's connection to Canadians thus far has been based in large measure on his ability to project hope and a sunny idealism that politics doesn't have to be nasty, mean and brutish.

But his central role in the cut and thrust of question period will put his resolution to remain positive to the test. He hasn't always been successful in the past -- calling Environment Minister Peter Kent a "piece of (excrement)," for instance.

His resolve will be further tested by partisan attack ads and other mud that will inevitably be slung at him by the Conservatives and probably the NDP as well.

Trudeau admitted he's taking a gamble, akin to unilaterally disarming in the midst of war. But, while he doesn't intend to be pushed around without pushing back, he insisted he won't go negative.

"I'm not going to sit back but I'm also not going to be dragged down to the same level as they are because across the country I have seen Canadians sick and tired of the negativity and the fighting."