Partisan polarization, populist attitudes, and anti-democratic behaviors

Introduction On December 3, 2024, South Korean President Yoon Suk Yeol briefly declared martial law, triggering a four-month constitutional crisis that culminated in his impeachment by the Constitutional Court. While martial law was the triggering event, the principal axis of partisan conflict that crystallized in its aftermath was support for or opposition to presidential impeachment. Methods Using the Korean Voter Panel Survey Wave 1 (February 25–28, 2025; N = 1,636), this study tests seven hypotheses about the individual-level predictors of anti-democratic justification—the willingness to justify undemocratic means to pursue political goals. Results We find that (1) rule of law commitment is the strongest protective predictor; (2) affective polarization (emotional hostility toward those holding the opposing impeachment position) substantially increases justification; (3) partisans of both major parties score higher than independents, but the effect of affective polarization is asymmetric—stronger among People Power Party supporters than among Democratic Party supporters; and (4) populist attitudes operate in two theoretically distinct ways, functioning both as a direct predictor and as a moderator that amplifies the effect of affective polarization while attenuating the protective effect of rule of law commitment. Discussion Importantly, we find limited attitude polarization—both camps share a baseline normative rejection of anti-democratic means—while affective polarization robustly predicts individual-level variation. This distinction may help explain South Korea’s capacity for rapid democratic recovery.