The redrawing of Canada’s electoral boundaries and the addition of 30 new ridings for 2015 through redistribution means the election map has changed a lot since the Conservatives won their majority in 2011. The changes add another layer of unpredictability for an election year. The purpose of redistribution is to try to ensure each riding represents roughly the same number of people, taking into account political and constitutional requirements. Prince Edward Island keeps its four seats, despite its small population, while Ontario adds 15 new ridings for 2015, B.C. and Alberta each get six more and Quebec gets three. But there is more to it than that. The boundaries in 70 per cent of the remaining ridings in the country have changed. Many of the riding names have changed, too. (You can find maps of all of them on Elections Canada’s website.)
As part of the process, the individual poll-by-poll riding results from the most recent votes (including byelections) were re-assigned based on the new boundaries across all 338 ridings.
That leads to some drastic, if hypothetical, changes in a handful of seats.
For example, if you live and vote in the riding of Winnipeg North, in 2011 your riding elected a Liberal, Kevin Lamoureux, with a margin of just 44 votes. Using those same 2011 votes, based on the new boundaries that riding now would elect a New Democrat by a 108-vote margin.