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Legislative Party Switching and the Changing Nature of the Canadian Party System, 1867–2015

  • Semra Sevi (a1), Antoine Yoshinaka (a2) and André Blais (a1)


In this paper, we investigate the phenomenon of party switchers in the Canadian House of Commons. With the most extensive dataset on party-switching MPs (1867–2015), we answer the following questions: What are the electoral trajectories of party switchers? Have their prospects changed over time? We assess whether the historical dynamics of the Canadian party system explain changes in the incidence and fate of party switchers since 1867, hypothesizing that both the rate of party switching and the electoral fortunes of floor crossers decline over time. The evidence accords with our second hypothesis more strongly than our first. Party switching has become slightly less common, but the electoral consequence has become much more severe.

Dans le présent article, nous examinons le phénomène des députés qui abandonnent leur formation politique à la Chambre des communes du Canada. Disposant de l'ensemble de données le plus complet sur les députés transfuges (1867–2015), nous répondons aux questions suivantes : quelles sont les trajectoires électorales de ces transfuges? Leurs perspectives ont-elles changé au fil du temps ? Nous évaluons si la dynamique historique du système de partis canadien explique les changements dans l'incidence et le sort des transfuges depuis 1867, partant de l'hypothèse qu'aussi bien le taux d'abandon que leurs destinées électorales diminuent avec le temps. Les éléments de preuve s'accordent avec notre deuxième hypothèse plus qu'avec notre première. Les abandons de parti sont devenus un peu moins fréquents, mais les conséquences électorales beaucoup plus graves.


Corresponding author

Département de science politique, Université de Montréal, 3150 rue Jean-Brillant, Montreal QC, H3 T 1N8, email:
Deparment of Political Science, University at Buffalo, SUNY, 418 Park Hall, Buffalo, NY 14260, email:
Département de science politique, Université de Montréal, 3150 rue Jean-Brillant, Montreal QC, H3 T 1N8, email:


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Earlier versions of this article were presented at the 2016 and 2017 Canadian Political Science Association Meetings in Calgary and Toronto and at the 2017 Making Electoral Democracy Work Annual Meeting in Montréal. We would like to thank the editors and the journal's anonymous reviewers for their helpful comments and suggestions as well as Vincent Arel-Bundock, Christopher Cochrane, Ruth Dassonneville, Jean-François Godbout and Can Mekik.



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Legislative Party Switching and the Changing Nature of the Canadian Party System, 1867–2015

  • Semra Sevi (a1), Antoine Yoshinaka (a2) and André Blais (a1)


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