Fertile Ground, but for How Long? The Volatile Role of Protest for Populist Challenger Party Success

This paper explores the role of anti-government protests in the rise of challenger populist parties, as well as the volatility of such movement-based support. The analysis is based on a case study of the farmers' protests in the Netherlands since 2019, examining their relationship with the rise and decline of the populist Farmer-Citizen Movement (BBB). Relying on panel survey data, behavioural data and municipal voting records, I use difference-in-differences models to analyse how the protests transformed the grievances of a small farming community into widespread populist sentiment that the BBB was able to mobilise in subsequent elections. I then explore the reasons behind the BBB's rapid electoral decline in the 2023 general elections. I argue that the openness of the movement's populist claims enabled more radical right parties to strategically insert their own claims, thereby winning over the support base. This study contributes to our understanding of the opportunities and risks for populist challenger parties that rely on protest movements for mobilisation, with implications that extend well beyond the Dutch case.