Stochastic terrorism, partisan campaign (mis)perceptions, and radical negative partisanship

Scholars have drawn attention to the rise of a radicalized partisan mindset, or negative radical partisanship (NRP), in which political opponents are seen as illegitimate, immoral, or even dangerous, and thus undeserving of democratic protections (Nai et al., 2025). While more attention has focused on the psychological and contextual roots of such partisan radicalization, the role of elite rhetoric remains underexplored. Can the “violent” ways in which political leaders speak about their opponents contribute to radicalized partisan attitudes? We investigate this question through the lens of stochastic terrorism – a form of indirect incitement in which political leaders use dehumanizing, moralizing, or threatening language against their opponents without explicitly calling for violence (Amman & Meloy, 2024). What makes this rhetoric especially dangerous is not just its content, but its ambiguity. Because it operates through suggestion, implication, and emotional appeals, it allows speakers to signal aggression while maintaining plausible deniability (Amman & Meloy, 2024). Drawing on social identity theory (Tajfel & Turner, 2004) and motivated reasoning (Taber & Lodge, 2006), we argue that this rhetorical ambiguity opens the door to systematic partisan misperceptions: supporters may minimize violent rhetoric from their own side, while exaggerating similar behaviour by the opposition. We further propose that individuals who fail to detect violent rhetoric from their in-group, or who over-attribute it to their out-group, may be more susceptible to its radicalizing effects. Using high-quality original data from a rolling cross-sectional voter survey (N=3,100) and a parallel expert survey retracing the evolution over time of campaign rhetoric (N=460), both fielded in parallel over the months leading to the 2024 U.S. presidential election, we examine how voters (mis)perceived indirect but violent rhetoric by the Democratic and Republican tickets, and how these perceptions then related to their levels of negative radical partisanship.Our results show that, voters systematically underestimated the use of stochastic terrorism by their in-party candidates and overestimated it by their out-party candidates. Moreover, these perception gaps mattered: individuals who overestimated violent rhetoric by their out-party candidates exhibited significantly higher levels of NRP. Contrary to expectations, underestimating in-party rhetoric was negatively associated with radicalization, suggesting a more complex causality between sympathetic perceptions of violent rhetoric and radical partisanship in individuals. References Amman, M., & Meloy, R. (2024). Incitement to Violence and Stochastic Terrorism: Legal, Academic, and Practical Parameters for Researchers and Investigators.Terrorism and Political Violence, 36(2), 234-245, Nai, A., Van Erkel, P. F., & Bos, L. (2025). Turning up and down the partisan heat. Voters’ psychological profile and changes in negative radical partisanship over the course of an election. Electoral Studies, 95, 102926. Reiljan, A., Garzia, D., Da Silva, F. F., & Trechsel, A. H. (2023). Patterns of Affective Polarization toward Parties and Leaders across the Democratic World. American Political Science Review, 118(2), 654–670. Taber, C. S., & Lodge, M. (2006). Motivated skepticism in the evaluation of political beliefs. American journal of political science, 50(3), 755-769. Tajfel, H., & Turner, J. C. (2004). The Social Identity Theory of Intergroup Behavior. In Political Psychology (pp. 276–293).