Pushed to the edge: When radical political messages persuade more on social media.

This study investigates how the persuasiveness of political messages depends on the platform context.Building on congruity theory and political acrophily, we examine whether political moderates (i.e., people with a centrist political orientation) are more persuaded by moderate or radical messages when encountered on social media versus legacy news websites.Two preregistered experiments (N = 208 and N = 269) show a consistent interaction: Moderate messages are more persuasive on legacy news websites, while more radical but still ideologically congruent messages are more persuasive on social media.Study 2 further reveals that this effect is mediated by heuristic information processing, which typically occurs in social media environments.These findings challenge the assumption that persuasion increases with strict ideological congruence and suggest that the dynamics of political persuasion are shaped by both message style and platform-specific processing.The results have implications for the refinement of persuasion theory in digital contexts.