Bloc supporters who did not rank the NDP second did so on the third ballot, while most of the others went with the Liberals. On the fourth ballot, the Conservatives were the preferred option. For Greens, the Liberals were the main third choice while fringe parties were most likely to be ranked fourth.
How many seats would they win?
But how would this all play out in terms of seats? When Abacus Data asked respondents who they would support on a standard ballot, the Conservatives and New Democrats were neck-and-neck (32 to 31 per cent, with the Liberals at 24 per cent). With those levels of support, the Conservatives would likely win 139 seats, the New Democrats 115, and the Liberals 82 on the 338-seat electoral map and using ThreeHundredEight.com’s seat projection model.
With a preferential ballot, however, the Conservatives would come out further ahead. They would lead in 147 ridings on the first ballot (after distributing the marginal support for the smaller parties), compared to only 108 for the New Democrats, 76 for the Liberals, four for the Bloc Québécois, and three for the Greens (primarily due to an anomalous result in the poll in Atlantic Canada).
The Conservatives would have majority support in 60 ridings and win those automatically, while the NDP would win 23 seats on the first ballot and the Liberals 11. But that Tory advantage would disappear once the instant run-off was conducted.
The Conservatives would lose their first ballot lead in 30 ridings, and be reduced to only 117. The New Democrats would move ahead in 18 more seats and take 126, while the Liberals would win 17 more ridings and increase their total to 93. The Greens would hold on to two of the three seats in which they led, while the Bloc Québécois would lose all four.
The inability for the Conservatives to grow after the first ballot is particularly marked in Ontario and on the Prairies. In Ontario, the Conservatives would drop 16 of the 49 ridings in which they led but did not have a majority on the first ballot, with those being split between the Liberals and New Democrats. In the Prairies, they would lose all six of the ridings in which they led on the first ballot but did not have majority support.
Tory growth beyond the first ballot is so limited that having even 42 per cent support in some Ontario ridings on the first ballot would not be enough to ensure a victory after the instant run-off is conducted. By comparison, the Liberals and New Democrats would only lose ridings in which they led on the first ballot to each other – never the Conservatives.
The Bloc Québécois is similarly limited. Though the party is the consensus second choice for New Democrats in Quebec, in the majority of ridings the Liberals, Conservatives, and Greens drop off first. The Bloc has little down-ballot support from these parties, and so is often unable to do better than 35 per cent in ridings where their candidate faces-off against the NDP on the final ballot.
This system of voting would make electoral co-operation between the opposition parties unnecessary, as the effect is much the same. But would the conduct of an election be different if the parties were campaigning knowing that a preferential ballot was going to be used?
Would the Conservatives move towards the centre in order to attract more second- or third-choice ballots? Would the Liberals campaign on the right to get more Conservative support, or would they move towards the left? And how would the Bloc campaign if support from Liberal and Conservative voters was needed?
This need for a wider tent is one of the benefits often cited by proponents of alternative voting. The necessity of second- and third-ballot votes encourages parties not to alienate non-supporters. It also ensures that each riding is represented by an MP that a majority of constituents preferred to the next most popular candidate.
Because of how this method of voting would limit the ability of the Conservatives to win elections, it is unlikely that it will be adopted while they are in power. The New Democrats prefer mixed-member proportional representation. The Trudeau-led Liberals may push for this kind of change. However, all three parties may lose their enthusiasm for any kind of democratic reform of a system that puts them into office. But if it ever is adopted, electoral politics in Canada could be unrecognizably transformed.
Éric Grenier writes about politics and polls at ThreeHundredEight.com .