The belief in the capabilities of one’s own group is crucial for joining collective action aimed at addressing large-scale societal crises like climate change. Drawing from the two-step flow of communication theory and behavioral models of collective action, we conducted two experimental studies and an innovative quasi-experimental field study (total N = 2,960). Across these studies, influencer messages increased collective response efficacy beliefs and political action intentions, particularly among followers with strong parasocial ties. Moreover, repeated exposure to an influencer’s message reinforced these effects. Our research underscores the potential of influencers in mobilizing collective political action within digital media environments.
