The border between Justin Trudeau's riding and Tom Mulcair's sits on a desolate strip of railroad track in the north end of Montreal. It's a no-man's land lined by broken-down fences and overgrown weeds.

North of the tracks is the Trudeau riding of Papineau, one of the poorest, most densely populated ridings in the country.

To the south, Mulcair's riding of Outremont. It has pockets of poverty, but overall is wealthy, with stately homes and exclusive private schools.

At first glance, the ridings seem an awkward fit for the men who represent them.

In fact, Justin Trudeau had his eye on Mulcair's Outremont when he first considered entering politics. His roots there were deep. He had gone to school at prestigious Brébeuf College, was married at Sainte-Madeleine d'Outremont Church and was living in the borough with his wife Sophie Grégoire.

He also briefly considered neighbouring Mount Royal riding, long held by his father Pierre Elliott Trudeau and pretty much impregnable as a Liberal stronghold.

For the first time since Confederation, two leaders are running in ridings that are right next to each other. 2:49

But Mount Royal was already held by the popular Irwin Cotler and the Liberal Party didn't seem overly eager to hand Trudeau a bastion, so he ended up fighting for the nomination, against the party's choice, in hardscrabble Papineau.

Oddly enough, it ended up being a good fit.

Trudeau's ability to connect personally with voters has made him popular. He credits his mother's father, Jimmy Sinclair, a long-serving Liberal MP and fisheries minister from B.C., for his populist approach.

Also, the Parc Extension section of Papineau is home to many different cultural communities — and they are still grateful for the multiculturalism policies that Pierre Trudeau brought in during the 1970s.

Outremont

Outremont was a Liberal bastion — held by the party for most of the last century. Progressive Conservative Jean-Pierre Hogue managed to take the riding in 1988, but it went Liberal again in 1993 and stayed that way until the NDP swept in during a 2007 byelection.

Tom Mulcair became only the second person ever elected as a New Democrat in Quebec history. (The first was Phil Edmonston, a popular consumer advocate, in a 1990 byelection. He did not run for re-election in 1993).

Jack Layton and Thomas Mulcair, shown here with candidate Anne Lagaçé Dowson in the 2008 election, together laid the groundwork for the NDP's Quebec breakthrough in 2011 in which 59 New Democrats were elected in the province. (Andrew Vaughan/Canadian Press)

Mulcair has some connection to the riding. His uncle, also named Thomas Mulcair, has his name on the Outremont cenotaph. (He died during an air force training accident during the Second World War.)

But Mulcair himself was born and spent the early part of this life in the Gatineau region, then spent many years in Laval. He had to work hard to put himself through law school in Montreal and then after graduation, moved to Quebec City to work as a civil servant.

Both Mulcair and Trudeau are popular in their ridings but face a particular challenge in this election. For the first time, they are not just the incumbent MPs, but also party leaders.

In fact, it's the first time since Confederation that two federal leaders have run in adjacent ridings.

That means they are high-profile but also much absent, with less time for the race at home.

Trudeau's got the tougher fight

However, Mulcair's grip on Outremont is so strong that his campaign team — along with organizers in two other NDP ridings — is funnelling resources to the NDP candidate running against Trudeau in Papineau.

That is broadcaster Anne Lagaçé Dowson. And while pollsters expect Trudeau to hold onto his riding, she says she's a serious threat.

"We've got a lot of volunteers, we've got a serious campaign on the ground, and we're taking this very, very to heart," said Dowson.

"We've got the lists, we've got supporters in the community groups, and there's a lot of curious and interested voters. We intend to be super visible on the ground and that's something the NDP does super well."

Anna Gainey, daughter of Montreal Canadiens great Bob Gainey and a Justin Trudeau confidante, is the new Liberal Party president and is helping run Trudeau's Papineau campaign. (Ryan Remiorz/The Canadian Press)

The Liberals may not have Trudeau to roll out that often, but they do have an army of volunteers.

On a recent visit to the campaign headquarters on busy Parc Avenue, there were dozens working the phones. Liberal Party president Anna Gainey says Trudeau can't be there to campaign, but others are there for him.

"We've had great volunteer support in this riding for many years, so they're experienced, they're engaged, they're motivated, they're really excited for Justin and to be a part of this campaign," said Gainey. "We rely on a great campaign team and a great group of volunteers to knock on doors and to make those calls."

Montreal is also home to a third federal leader.

Gilles Duceppe is again running for the Bloc Québécois in Laurier Sainte-Marie, about a kilometre south of where Papineau and Outremont meet.

In 2011, he and his party were stunned by the so-called Orange Wave of New Democrats who swept 59 of Quebec's seats.

Duceppe lost his own seat to Hélène Laverdière and resigned as party leader. But with the Bloc sinking even deeper in the polls, he decided to attempt a comeback. This time, the party has more modest goals — reportedly focusing on just 30 ridings. One of them is his.