--- - |2+ Objectives The objective of this study was to understand the effect of citizen mobilization on both electoral outcomes and on the likelihood that new candidates will enter races to challenge incumbent politicians. Methods This study uses quantitative, longitudinal data (at the congressional‐district level) on protest, electoral outcomes, and challengers entering races, which are analyzed using an autoregressive distributed lagged regression model. Results Results show that protests that express liberal issues lead to a greater percentage of the two‐party vote share for Democratic candidates, while protests that espouse conservative issues offer Republican candidates a greater share of the two‐party vote. Additionally, results indicated that protest shines a light on incumbent politicians’ failure to address constituent concerns, which leads quality candidates to enter subsequent races to challenge incumbent politicians. Conclusions Citizen activism, which has been shown to impact state and firm policy decisions, also impacts electoral outcomes. - Social Science Quarterly, EarlyView.