Fighting the Cabal from the Diet: Sanseitō and the Role of Conspiracy as Political Ideology

Abstract Sanseitō is a fringe Japanese political party founded during the coronavirus disease 2019 (COVID-19) pandemic that has won several seats in the National Diet since 2022. Initially coming to prominence as a promoter of anti-vaccine narratives, the party has since promoted a conspiracist worldview that connects to more conventional right-wing nationalism and addresses a much broader range of issues and beliefs. In this article we outline the core tenets of this worldview and examine how attention to its construction as a participative political ideology sheds light on the party’s political actions and motivations.