Breaking the country into four blocs - the West, Ontario, Québec, and the Atlantic - is practical as the four contituent parts each hold a large amount of seats (at present 92, 106, 75 and 32 respectively), and as they're each terms with historical merit ('The West' is the most nebulous term, really, consisting of four provinces each with very distinct voting trends, but when totalled, trends do emerge).
In this exercise, I've gone back to Diefenbaker's 1958 landslide, and in each case I've looked at the total number of seats per party returned in each of the four regions, and I've also considered what Parliament would look like if it were composed of the whole country minus the region in particular. In other words, a "minus-Ontario" result would be the combined seat totals for the West, for Québec and for the Atlantic (the North as well - in each case I include the North's three seats in relevant national totals, but otherwise ignore them); as if Ontario had seceded from the union prior to the election.
The point of this math is to consider scenarios where the actual government formed by the election in question (which party, and whether it was a majority or a minority) differed from the "-Ontario" result; if removing Ontario from the equation would produce a different government than actually occurred.
The overview results are interesting themselves: In 17 elections, the nation as a whole has returned 6 Liberal majorities and 4 Liberal minorities, 3 PC majorities and 2 PC minorities, and two Conservative majorities. So Liberal domination, but a relatively healthy bipartisan mix. Looking at the regions, though, shows quite a difference: the Atlantic considered alone returned 9 PC majorities, 8 of them straight, between 1958 and 1984; after that, they switched teams decisively, electing 7 liberal majorities, interrupted by their only plurality: the surprising result in 1997 when the Atlantic returned a plurality of PC MPs.
Québec looks similar. Though they went PC for Diefenbaker and Mulroney (being largely responsible for Canada's only two near-consensuses in recent history), otherwise it was Liberal pre-Mulroney (7 straight majorities, one plurality) and BQ post-Mulroney (6 straight majorities). The West, despite an amazing volatility in BC and intermittently strong NDP results in Saskatchewan and Manitoba, have been remarkably consistent in their affections. Trudeaumania took over BC in 1968 enough to return a Liberal plurality, but otherwise it's been non-stop PC majorities from 1958 to 1988, non-stop Reform/CA/Conservative majorities since.
That leaves Ontario, which perhaps is the Bellwether, based on how consistent the other three regions have been. Ontario has returned 11 Liberal majorities, 2 PC majorities, 2 PC pluralities and 1 Conservative plurality.
Overall, the West has swayed the winning party on three occasions (1962, 1979 and 2006), while Ontario has done so on three occasions (1979, 1997 and 2004), and Québec on four occasions (1963, 1965, 1972 and 1980 - remarkably a Québec-less Canada would have returned the PCs every year from 1958 to 1988 except in 1968). The Atlantic since 1958 have not once swayed an election.
Looking down the years, then:
- In 1958, Diefenbaker won a decisive majority. Each region gave a majority of seats to the PCs, so obviously each 'minus parliament' also did so. It's interesting that while the Liberals tend to be 'Canada's natural governing party', the only true landslide sea-to-sea consensuses we've seen have both been PC.
- 1962 brought a PC minority, the first of three minorities. The coasts stayed majority-PC, while Ontario returned a Liberal majority and Québec a Liberal plurality. 1962 definitely shows that the 'Central Canada' thesis has holes in it: Ontario and the Atlantic had no affect, while Québec held the PCs to a minority (a minus-Québec parliament would have returned a PC majority) and the West actually chose the PM (a minus-West parliament would have been Liberal minority).
- 1963, though, shifts the numbers just enough to prove the West's point: a Liberal minority brought about by the coasts returning majority PC MPs and the 'centre' returning Liberal majorities. But the minus-numbers tell an interesting story. Again, Ontario and the Atlantic had no effect, while the West this time kept the Liberals to a minority and Québec turned the tides, from a PC minority to a Liberal one.
- 1965 was another Liberal minority, and everything I've said for 1963 applies here too, except that a minus-Atlantic parliament would have been an even split: 116 Liberals to 116 'others'. I think technically that's a Liberal minority, but I'm not entirely sure how to classify it.
- 1968 is Trudeau's big year, and a Liberal majority. It's interesting to note, looking back, that Trudeau's party-poopers were not the West so much as the Atlantic. The West brought a threadbare Liberal minority, while the Atlantic decisively stuck with favourite son Robert Stanfield, giving his PCs 25 in 32 seats. 'Central Canada', of course, went deep red. This was a Liberal majority, and no single region could have changed it from a Liberal majority.
- Trudeau won 1972 too, but by two seats. The Atlantic kept its PC majority, the West returned to a PC majority (never again to waver), and Ontario went to a PC plurality. Thus, it seems like 1972 was Québec's year, with their decisive Liberal majority keeping Trudeau at 24 Sussex. And indeed, Ontario and the Atlantic had no effect, while the West held Trudeau to a majority, and a minus-Québec parliament would have been a PC majority.
- In 1974, Trudeau got his majority back, and the numbers are similar, just shifted in the Liberals' favour. PC majorities in the West and Atlantic, Liberal majorities in Québec and Ontario, and the notion that 'Central Canada' runs the country quite firmly established by now. This is certainly the case in 1974, with neither the West nor the Atlantic having any sway, with Ontario enough to shift it from a Liberal minority to a Liberal majority, and with Québec's vote enough to move from a PC minority to a Liberal majority.
- 1979's PC minority was interesting. This time out Ontario joined the West and the Atlantic in returning PC majorities, while Québec returned another Liberal majority. Only the Atlantic had no sway this time: were it not for the West, the PC minority would have been a Liberal majority. Were it not for Ontario, the PC minority would have been a Liberal minority. And were it not for Québec, the PC minority would have been a decisive majority. No wonder the government was doomed to failure.
- 1980 brought Trudeau decisively back, with another Liberal majority. With the West returning only two Liberals and Québec only one PC (PC majority and Liberal majority respectively), it increasingly looks like Ontario really is the kingmaker, its fickle preferences dictating results when the West and Québec are so decisive in their support for their 'home teams'. In fact, both it and the Atlantic 9for the first time) went Liberal-majority. Only Québec can lay claim to holding sway, though, as minus-parliaments for the other three regions still return Liberal majorities, while a minus-Québec again brings a PC minority.
- 1984 is our second landslide, with Mulroney's PCs gaining a majority in each region (in each province and territory, in fact) and reducing the Liberals to 40 seats. There's little to say here - electing Mulroney was a nation-wide effort, and no individual region could have stemmed that tide (or wanted to, as it transpired).
- 1988 was another PC majority, but less decisively. Ontario gave the PCs only a plurality, while the Atlantic returned a Liberal majority. With the West handing the NDP their best-ever result (while still going PC-majority, though), it seems like Mulroney had Québec to thank, proving that after years of kingmaking for the Liberals, La Belle Province could play kingmaker for the PCs too. Interesting, then, that after this election Québec will decisively turn away from affecting federal outcomes, remaining by and large on opposition benches henceforth. As it turns out, though, no single region kept Mulroney in power. A minus-Québec would have still been PC, but minority, while the other three regions had no effect.
- 1993, of course, is where everything changed. I imagine most Canadians old enough to remember could tell you that Ontario and the Atlantic sent decisive Liberal majorities, while the West sent a Reform majority and Québec a BQ majority. What all this means, though, is that ultimately not one region could be said to have turned this election, however it appears. A minus-West election and a minus-Québec election would have unsurprisingly returned Liberal majorities. So would have a minus-Atlantic parliament. A minus-Ontario parliament would have returned a minority, but the Liberals would still have won it.
- 1997 was perhaps even more interesting. The only regional overall change from 1993 was that the Atlantic went plurality-PC (thus each of the four regions preferred a different party). Like last time, neither the West nor Québec nor the Atlantic could have prevented a Liberal majority, but this time the majority was all Ontario's - two-thirds of Chrétien's MPs were from Ontario. A minus-Ontario parliament would have returned, of all things, a Reform minority. But it would have been almost completely dysfunctional, with 60 Reform MPs, 54 Liberals, 44 Bloquistes, 21 New Democrats and 19 PCs. God know what kind of bills, if any, that parliament could pass.
- 2000 was 1993 again: Liberal majorities in Ontario and the Atlantic, a barebones BQ majority in Québec, and another majority for the Party-Formerly-Known-as-Reform in the West. A Liberal majority, that without Ontario would have been a minority, but otherwise no region could have changed.
- The Liberals won in 2004 too, if a minority mandate can truly be called 'winning' and 'merely not losing'. The regions once again still look the same, though that western party is now called the Conservatives. Neither Québec nor the Atlantic could have swayed a Liberal minority, but but for the West it would have been a Liberal majority, and but for Ontario it would have been a Conservative minority. As indeed it was about to be.
- 2006 brought Harper's Conservatives a minority, elected through regional majorities: the BQ in Québec, the Liberals in Ontario and the Atlantic, and the CPC in the West. So while all four regions have returned the exact same results in each of the previous three elections, the result has shifted from Liberal majority to Liberal minority to Conservative minority. And quite clearly the West were kingmakers this time, as no other region could have prevented a Conservative minority, but a minus-West parliament would have been another Liberal minority.
- By 2008, the Conservatives had been able, with a pickaxe, to slowly pick away at Liberal support in Ontario to the point that this time out they'd tipped the balance - a CPC plurality in Ontario. The other three regions have stuck with their favourites for the sixth time in a row (excepting the Atlantic in 1997) though, suggesting again that Ontario is where elections are made and broken. In fact, though, we have Québec to thank for the current government makeup. None of the West, Ontario or the Atlantic could have changed a CPC minority, but were it not for Québec, Harper would have had his long-dreamed-of majority.
What to do with all this information? Well, what it shows me is that the West is more of a kingmaker than Westerners might think but that ultimately Québec wields the most power - especially before the birth of the BQ. It's also interesting to see just how little power the Atlantic actually have. Unsurprising, perhaps, in terms of overall numbers, but seeing how independent-minded they can be, still unexpected.