Why would individuals engage in or support contentious politics? This question is challenging to answer with observational data where causal factors are correlated and difficult to measure. Using a survey-embedded experiment, we focus on three situational factors: grievances, risk, and identity. We also explore how individual differences in sociopolitical orientations—social dominance orientation (SDO) and right-wing authoritarianism (RWA)—impact action. Grievances influence engagement in and support for protests. Risk influences engagement in protest, but not support for it. Regardless of condition, SDO and RWA help explain why some people engage in protest while others do not, particularly within the same context.