Overcoming impeachment hurdles: elite polarization, mass mobilization, and corruption scandals

Abstract Presidential impeachment has traditionally been seen as a clear manifestation of accountability. Recently, however, the impeachment of some presidents has sparked public backlash. This article highlights the importance of elite affective and ideological polarization in explaining presidential impeachment. We theorize impeachment as a multi-hurdle process and focus on examining the determinants of overcoming two primary hurdles: a pro-impeachment lower house vote and removal from office. The article employs crisp-set qualitative comparative analysis (QCA) to examine 44 cases of successful and failed impeachment. The results uncover three types of impeachment: polarized, scandalized, and mobilized impeachments. Notably, elite polarization, be it affective or ideological, is the primary trigger of impeachment in several cases and the facilitator of impeachment in the presence of other triggers such as corruption scandals or mass mobilization. While both ideological and affective polarization facilitate a pro-impeachment vote in the lower house, it is affective polarization that drives removal from office primarily in the absence of a legislative shield. We use two illustrative cases to demonstrate polarized impeachment: Donald Trump in 2019 and 2021, and Dilma Rousseff in 2016. The findings withstand a wide range of robustness tests, including sensitivity ranges, consistency thresholds, fit-oriented robustness, and cluster analysis. Given the rise of affective polarization worldwide, presidential impeachment may be increasingly weaponized by polarized elites.