Harper was also hurt by what has become a five-party political system in Canada.

"It's very difficult to get a majority in this 'pizza Parliament,' " Wiseman said.

Under proportional voting systems, countries often get "pizza parliaments", so called because a seating map of the legislature resembles a pizza cut into many pieces. In pizza parliaments, even the biggest parties rarely have enough seats to form a government and they are forced into alliances with smaller parties.

What may happen is that two small regional parties, which opposed the constitutional changes, will win many seats away from the established parties in the next national election. Saskatchewan Premier Roy Romanow described the likely result as a "pizza Parliament" with a number of unmanageable ingredients.