The by-election in Calgary Centre that comes to a close on Nov. 26 has unexpectedly become the focus of a lot of attention, as the race appears to be far closer than most would have thought possible in deep Tory blue Alberta. If the unthinkable happens, how would a Conservative defeat compare with some of Canada's biggest historical by-election upsets?
Calgary Centre has elected conservative candidates of one stripe or another since it was first created in the 1960s. Depending on how you trace the riding's lineage through boundary changes over time, that streak stretches all the way back to the Second World War. In 2011's federal election, Conservative MP Lee Richardson was re-elected with 58 per cent of the vote. Liberal candidate Jennifer Pollock placed second with 18 per cent.
The idea that Calgary Centre could be lost by the Conservatives might seem far-fetched, but polls released this month suggested that the race is incredibly close. A poll released Sunday by Forum Research gave the Conservatives' Joan Crockatt only 35 per cent support to 30 per cent for Harvey Locke of the Liberals. That five-point edge is about the size of the poll's margin of error.
But putting aside this poll, there are other signs that the riding is in a state of flux. Reports of a split between supporters of the provincial Wildrose and Progressive Conservative parties have emerged, with Ms. Crockatt being seen within the Wildrose wing of the party. She also missed an all-candidates forum last week and was then publicly urged by popular mayor Naheed Nenshi to attend a debate he had organized Sunday when she was the only candidate that had not yet accepted his invitation. In the end, she attended a different debate on Saturday instead.
The Liberals did manage 30 per cent support as recently as 2004 and their provincial counterparts have won elections within the boundaries of the federal riding. But the Liberals were 40.2 points back of the Tories last year. Overcoming a margin of that magnitude would make their victory one of the largest upsets in Canadian history.
One for the history books
In only five other by-elections since Confederation has a party managed to overcome a margin of more than 40 points. The most recent was in 2010, when the Liberals' Kevin Lamoureux overcame a 53.4-point margin in Winnipeg North, defeating the incumbent New Democrats.
The largest margin that has ever been overcome in a by-election was in 1987, when Jack Harris (who returned to federal politics in the 2008 election) turned around a 71.7-point deficit to unseat the Progressive Conservative candidate. The other by-election upsets took place in Peterborough in 1960, Humber-St. George's-St. Barbe in 1978, and Yukon in 1987.
If Ms. Crockatt is defeated, it would rank as Canada's sixth greatest by-election upset in terms of the vote margin. But the consecutive string of victories it would end would put the others to shame: 23 consecutive elections have been won by Conservative, Reform/Canadian Alliance, or PC candidates in the riding and its predecessors. By comparison, of the five by-elections where a larger margin slipped away the longest string of victories ended was 11, when Audrey McLaughlin of the NDP ended 30 years of Tory dominance in the Yukon riding.
The most comparable by-election would be the 1952 win in Gloucester by the Tories, who overcame a 39.6-point margin to end 56 years of Liberal occupancy of the riding.
But the Liberals are not the only party in the running for Ms. Crockatt's seat. Chris Turner of the Greens placed third in the Forum poll with 25 per cent, 10 points behind Ms. Crockatt. That gap is just outside the margin of error, but the Greens have been running a very active campaign in the riding and have managed as much as 17 per cent support as recently as the 2008 election.
If Mr. Turner managed the upset, he would have overcome the 47.8-point margin that existed between the Conservatives and the Greens in the 2011 election. That would rank as the fifth biggest upset in Canadian by-election history, though a win by the Greens in Alberta might rank as an even bigger surprise from an ideological perspective.
There are other by-elections where parties had completely unexpected results, but because of their special circumstances are not comparable to this by-election in Calgary Centre. For example, in 1949 the Liberals lost the riding of Kamouraska, which they had won by 55.8 points in the previous general election, due to an Independent Liberal being the only other opponent on the ballot. In 1943 the Liberals lost the riding of Cartier to the Labour-Progressive Party's Fred Rose after beating out the National Labour candidate in 1940 by 77.1 points, but the two parties were not the same (Mr. Rose was eventually convicted of spying for the Soviet Union).
The by-election wins by Deborah Gray for the Reform Party in 1989 and Gilles Duceppe for the (then-unrecognized) Bloc Québécois in 1990 also stand out as historical upsets for more reasons than just the numbers.
On the face of it, the stakes are quite low in Calgary Centre. If the Conservatives lose it will not change the order of the parties on Parliament Hill and could be the sort of one-off by-election upset that means little in the long-run. But historically, a defeat by the Conservatives in this riding would be one for the record books.
Éric Grenier writes about politics and polls at ThreeHundredEight.com.