The reason a majority is a reasonable expectation after the next election is because there will be fewer parties in the running for seats. In the 1960s there were four parties winning seats consistently and we have three minority governments. 2004 to 2008 saw three elections because we had four parties winning enough seats.
Here is what is possible for the NDP to win, not what they are going to win. Think of it as a best case scenario based on past federal and provincial elections and some realm of the reality of 2015.
- Cons NDP Libs other
- BC 14 27 0 1
- Alberta 30 4 0
- Sask 7 7 0
- Man 8 6 0
- Ontario 52 58 11
- Quebec 5 62 5 6
- New Brunswick 5 2 3
- Nova Scotia 2 5 4
- Newfoundland 1 2 4
- PEI 1 0 3
- North 1 2 0
- TOTAL 126 175 30 7
The total of 30 seats for the Liberals is not unreasonable for the #3 party in a three party race in Canada. When we had three main parties, the number of seats the NDP won was often around 10% of all the seats. I see them losing all their seats west of Ontario.
In BC it would not take much for the NDP to win the majority of the seats. In a primarily two way race the NDP would benefit the most from being in the lead with the vote. If the NDP leads the Conservatives in BC by 10 percentage points this the is the sort of split one would see.
In Alberta the NDP benefits from having all its vote concentrated in Redmonton. At the moment there are 8 Edmonton ridings, with the new seats that is likely to rise to 10. Not only will there be more seats to run in, several of them will likely be more NDP friendly. Six seats is a stretch, but not at all impossible to achieve especially as I think that Thomas Mulcair will actually play well in Alberta.
In Saskatchewan everything will depend on the redistribution. If it makes ridings more urban and rural and not as split, then the NDP will gain seats. The NDP will also benefit from being out of government in the province. The NDP has won as many as 10 of the seats in the province.
In Manitoba the NDP is a reasonably popular government. It would not take a large shift in votes for the NDP win four more seats.
Quebec, the polls are not indicating post election of Mulcair as leader that there is much life in the Bloc. The NDP will be better organized and should be able to gain some seats.
Atlantic Canada and the North - the NDP I suspect only has a chance to gain a few seats Nova Scotia and one more in New Brunswick.
Once again, Ontario will be crucial to who wins the next federal election. Based on the 1990 Ontario election, the NDP can win the majority of seats in Ontario. A squeeze on the Liberal vote by the NDP could easily cause the shift of many seats.