This study focuses on a paradox of federalism. In disputed policy issues, subnational government units can initiate bottom-up policy change while the federal government remains inactive. This typically occurs in public health or climate change fields, where there might be a mismatch between the required and the effective scale of action. In such cases, subnational entities bear the costs of a politically risky action to produce a higher-level public good. Based on a study of tobacco control in 14 Swiss member states, we investigate why some subnational governments take the lead, while others adopt a wait-and-see attitude. We find a set of four configurations favourable to state activism (window of opportunity effect, reallocation effect, innovative identity effect, regionalisation effect) and four unfavourable (municipal resource burden effect, diffusion of responsibility effect, local autonomy effect, economic dependency effect). These bottom-up dynamics are crucial for understanding collaborative policy processes.