In studies on stability and peace in multinational states, the relationship between regionalist parties and political conflict is a key topic. Yet, existing works left several blind spots. First, the effect of conflict on regionalist parties has hardly been investigated. Second, violent conflicts receive ample attention, but everyday clashes between politicians are rarely analyzed. Third, existing works are typically preoccupied with ethno-territorial clashes. The link between regionalist parties and other conflicts is largely neglected. Aiming to address these gaps, this project assesses whether conflicts at the central policy level benefit regionalist parties electorally. The project focuses on cabinet conflicts and consists of three parts. It assesses whether conflict benefits regionalist parties (RQ1), checks whether this effect depends upon the political opportunity structure (RQ2), and analyzes whether the nature of the conflicts matters (their timing, intensity, and ethno-territorial nature) (RQ3). To answer these questions, I establish an unprecedented dataset on cabinet conflicts in 9 Western countries (1990-2020). This allows me to assess the link between these clashes and the electoral results of 62 regionalist parties. To this end, large-N regression analyses are used (N= at least 385 – 476 individual regionalist parties at a given election; depending on the analysis). The resulting data and insights can fuel a wide range of societal and academic debates.