Some number crunchers suggest the New Democrats could hold a third of the bench-space in a reconfigured House of Commons after the May 2 election thanks to a dramatic surge in support that began mid-campaign.
But figuring out where those seats could be won is not easy. The burgeoning enthusiasm for Jack Layton's party could drop off - or grow - in these last few days. And vote splitting with the Liberals and the Bloc Québécois could create unforeseen outcomes.
Predicting which seats will be won and lost is a mug's game - but here is what we know about the concentration of NDP support and the places where the party could make gains.
That riding is "definitely in play for the NDP, and their surge may very well push them over the top there," said Alex Marland, a political scientist at Memorial University. However, he said, the other Newfoundland ridings are out of reach of the NDP.
This province holds some of the party's best opportunities for gains outside of Quebec.
In addition to keeping the two seats they already have, which seems likely, there are three more that could fall to the New Democrats, all in the greater Halifax area.
They are South Shore-St. Margaret's, which is currently held by Conservative MP Gerald Keddy; Dartmouth-Cole Harbour, which is held by Liberal Mike Savage; and Halifax West, which is held by Liberal Geoff Regan.
If all of the NDP stars were aligned and the orange tide truly swept through this province, NDP candidate David Parker could unseat Peter MacKay, the Conservative Defence Minister, in Central Nova. That seems unlikely at this point.
But James Bickerton, a political-science professor at St. Francis Xavier University, in Antigonish, N.S., said the other three seats are definitely in play.
It's not that the incumbent MPs in those ridings have been poor performers, he said. "It's this (orange) tide and the fact that the NDP has a very good, strong organizational base in the greater Halifax area," Prof. Bickerton said, "plus, very good candidates."
The NDP hold one seat here - Yvon Godin is a popular MP in Acadie-Bathurst - but the party does not seem poised to pick up any of the nine additional seats in the province.
Prince Edward Island
The NDP hold none of the four seats on the island and acknowledged that Mr. Layton's visit here during the campaign was largely a move to build support for the next election.
This is where the party could really put some notches in the win column.
A Nanos Research poll on Thursday suggested the NDP had the support of 42.5 per cent of Quebeckers. That is a very big number and, if it holds until election night, it will translate into seats. But how many and where is difficult to pinpoint.
The riding of Gatineau, which is held by the Bloc, seems like a sure thing for the NDP. The Liberal seat of Hull-Aylmer next door is also leaning New Democratic. And Foreign Affairs Minister Lawrence Cannon appears to be in trouble in Pontiac as the momentum drifts across the Outaouais region, north of Ottawa.
There are Bloc and Conservative seats near Quebec City that the party could pick up.
The riding of Abitibi-Baie-James-Nunavik-Eeyou could go orange on the strength of the candidate.
Antonia Maioni, a political-science professor at McGill University in Montreal, said there is a "contagion" factor from adjacent ridings that is putting Mr. Cannon's seat on the line.
The same thing is happening on the Island of Montreal, where the New Democrats had their lone Quebec seat before the writ was dropped, said Prof. Maioni. As a result, she said, Liberal Marc Garneau could lose Westmount-Ville Marie.
Across the province, there are two things going on, said Prof Maioni. "There is the die-hard Liberal voter that is being liberated from voting for the Liberals," she said. "And on the other side, there are the Bloc voters who are being liberated from the BQ."
The New Democrats made huge gains in Canada's biggest province in the 2008 election, when they swept through Northern Ontario claiming all but three seats.
And there is a possibility of pickups in this election. But there are also possible losses. Ridings such as Welland, in the Niagara Peninsula, and Sault Ste. Marie, in the north, could fall into the hands of other parties.
The New Democrats' best opportunities for increasing their seat count here is in Toronto, where they would like to win the three of ridings they don't currently own along the Bloor subway line in the southern part of the city. Mr. Layton and his wife, Olivia Chow, hold the other two.
Parkdale-High Park could move from Liberal Gerrard Kennedy to Peggy Nash, a previous incumbent. The Liberals could also lose Beaches-East York, which the NDP has coveted for years. And Liberal MP Mario Silva could fall in Davenport.
"Right now, Ontario is still in flux," said Nelson Wiseman, a political-science professor at the University of Toronto. "Their vote is going to pick up, but that's going to tip a number of seats (from the Liberals) to the Conservatives."
The New Democrats hold three seats here and appear headed to pick up a fourth in Winnipeg North, which was just won by the Liberals in a by-election last fall after being in NDP hands for many years. The party is running Rebecca Blaikie, the daughter of popular former NDP MP Bill Blaikie, and she appears to have the edge.
The Conservatives currently hold every seat in this province except one: Wascana, which is the long-time domain of Liberal Ralph Goodale.
But that could change on election day. At least three seats could fall to the New Democrats: Palliser and Saskatoon-Rosetown-Biggar, near Saskatoon, and Desnethé-Missinippi-Churchill River, in the north.
David McGrane, a political scientist at the University of Saskatchewan, said there is obvious momentum in this province for the NDP.
"The question is, is that momentum going to translate to increased voter turnout for NDP voters?" Prof. McGrane asked. "You can start to see some Liberal voters starting to shift towards the NDP. The problem (for the party) in Saskatchewan is, there are not a lot of Liberal voters."
This is the province where environmentalist Linda Duncan made a breakthrough for the New Democrats in Edmonton-Strathcona in 2008.
The NDP thinks it has a chance to expand their hold to Edmonton East, where Ray Martin is a popular candidate, and possibly Edmonton Centre, where they could unseat Conservative MP Laurie Hawn. But both of those are considered long shots
Conservative Indian Affairs Minister John Duncan is facing a strong challenge by New Democrat Ronna-Rae Leonard in Vancouver Island North, a seat that has recently been held by the NDP.
The New Democrats could also pick up Esquimalt-Juan de Fuca now that incumbent Liberal MP has retired.
And Dona Cadman, who held Surrey North for the Conservatives, could be displaced by New Democrat Jasbir Sandhu.
The New Democrats have big hopes for the interior of British Columbia - especially Kamloops-Thompson-Cariboo. But, unless the orange tide is exceptionally strong, those seats are likely to remain in Conservative hands.
The New Democrats are unlikely to pick up an additional seat in the North and are at risk in the Western Arctic, which they currently hold.