Several democracies around the globe have witnessed growing support for illiberal parties in recent years. Where do these parties generate their electoral support from? And when do voters withdraw their endorsement once illiberal parties have been voted into government and undermine democracy? I develop two mechanisms leading to growing and declining voter support for illiberal parties: communities’ economic performance and transforming civil society. The first mechanism conceives poor economic conditions as the primary driver of illiberal party support, while the second mechanism entails a weak civil society as a key electoral source of illiberal parties. To examine the empirical explanatory power of these two mechanisms, I provide evidence from time-series analyses of election returns for the Polish Law and Justice party at the county (powiat) level and panel and original survey data on Polish citizens’ political attitudes and behavior. The study has implications for the origins of illiberal party support and strategies to counter their electoral performance.