現代日本におけるポピュリスト志向と投票行動—2025年参院選での参政党躍進と2026年衆院選での自民党圧勝を中心に—

抄録

This study examines trends in populism in Japanese politics during the 2020s, focusing on the surge of Sanseitō in the 2025 House of Councilors election and the overwhelming victory of the Liberal Democratic Party (LDP) led by Sanae Takaichi in the 2026 House of Representatives election. Using data from a 2026 survey of residents in Tokyo’s 23 wards, the study analyzes the impact of populist attitudes on voting behavior. Statistical analysis revealed that the left-wing populist Reiwa Shinsengumi and the right-wing populist Sanseitō experienced significant growth during the LDP’s growing distrust. Reiwa Shinsengumi emerged first, followed by the rise of Sanseitō. In contrast, the LDP’s 2026 victory appeared to stem not from populism but from a resurgence of nationalistic individuals and young voters.