Previous research has shown that public opinion polls can be crucial in shaping voter behavior and political discourse. While polls inform voters and political elites about public preferences, they may also distort democratic processes by legitimizing and normalizing controversial political actors. This paper addresses this underexplored effect by investigating whether polls can legitimize previously stigmatized parties in voters’ eyes.

Focusing on the case of far-right parties, we theorize that increasing polling support for pariah parties signals legitimacy to voters, potentially enhancing these parties' acceptance and electoral appeal. To test this hypothesis, we combine two complementary analyses. First, using a novel dataset of over 250,000 polling values from 32 OECD countries, we employ trend detection techniques to demonstrate that far-right parties are disproportionately associated with prolonged upward polling trends. These findings suggest a possible self-fulfilling prophecy effect, whereby polling trends legitimize these parties. Second, we directly investigate polls’ influence through a survey experiment conducted in Germany, Spain, the Netherlands, and Denmark. Exposing respondents to different polling trends, we examine how these trends affect respondents’ perceived legitimacy and voting intentions toward pariah versus mainstream parties.

This study advances our understanding of the complex role of public opinion polls in modern democracies. We shed light on a so far neglected factor potentially driving the normalization and rise of pariah parties. This research underscores the critical role of opinion polls in shaping democratic resilience and highlights the need for reflection on their broader implications for democratic politics.