Political polarization and political violence/ James A. Piazza

Is political violence and support for political violence more prevalent in democratic societies with high levels of affective polarization? This study argues that affective partisan political polarization fosters dehumanization of opposing partisans, lends a moralistic and zero-sum nature to political life, and facilitates group mobilization. These all produce an environment in which political violence is both more socially acceptable and more frequent. The study tests this assertion using two sets of empirical tests: an original survey of 1,899 US residents and a cross-national time-series analysis of eighty-three democracies. It finds that in the United States, Democrats who express aversion toward Republicans are 8% more likely to express support for the use of political violence, whereas Republicans who express aversion toward Democrats are 18% more likely to endorse political violence. Furthermore, in the cross-national analysis, democracies characterized by higher levels of affective partisan political polarization are 34% more likely to experience frequent political violence.