Muddying the waters: how perceived foreign interference affects public opinion on protest movements

Does foreign interference help or harm protest movements? An extensive literature has debated this question but focuses on observational data, obscuring a crucial mechanism for protest success: its effect on public attitudes. We argue that public accusations of foreign meddling damage protest groups by reducing public support. In survey experiments conducted in the United States and Canada, we find that credible accusations of foreign interference erode support by discrediting protester groups among sympathizers and inflaming nationalist fears. Indeed, such accusations delegitimize protest movements even among those sympathetic to the cause. Conditional factors, such as the type of foreign assistance or the identity of the meddling state, have no impact. These findings reveal how referencing foreign backing is a potent discrediting tactic—it influences public opinion, a critical determinant for protest outcomes.