Who Intervenes in Supreme Court Cases in Canada?

Abstract With the patriation of the Constitution in 1982, the Supreme Court of Canada (SCC) inherited extraordinary political powers. In response to the Court's expanded power of judicial review, there was a sizeable increase in the number of political actors “intervening” in SCC cases. Scholars of Canadian law and politics are deeply divided on whether civil society participation in the courts—particularly as intervenors—is democratically legitimate. This important debate cannot be settled without an empirical evaluation of who intervenes. This research note provides an analysis of all the Charter cases heard by the SCC between 2013 and 2021. In contrast to the field's dominant theory on interest-group legal mobilization—the Court Party thesis—the findings reveal that equity-deserving interest groups, such as those representing women, have an irregular presence in Court. Instead, powerful actors such as governments and legal associations make up a majority of the “repeat player” intervenors. While further research is warranted, the research note concludes that without the maintenance of sufficient support structures, intervention may be unable to perform a democratizing function.