Deliberative minipublics are being considered as a potential solution to address the multiple challenges facing representative democracies. Their unique design of these participatory processes, combining civic lottery with structured deliberation, is believed to have positive effects on crisis of democracy. Nevertheless, these positive expectations are mostly theoretical and need further investigation to determine their actual effectiveness. This PhD thesis investigates the main function associated to minipublics, which is to form a considered collective will to influence public decision-making. The research makes conceptual, methodological, empirical and theoretical contributions. Firstly, it develops a conceptualization of the influences of minipublics by taking into account the initial preferences of decision makers and whether they cherry-pick recommendations. Second, it proposes a new analytical framework, the Sequential Impact Matrix, to measure the influences of minipublics and shows the importance of interviewing decision makers in order to trace causality. Empirically, it conducts a case study of the citizens’ panel “Brussels— Make your Mobility” and finds that the panel did have an important impact on the mobility plan “Good Move”. However, most recommendations were in line with the government’s agenda. The case study also highlights the need consider the broader political influence of minipublics beyond the adoption of policy recommendations. Theoretically, the PhD thesis reviews the literature on public policy and argues that minipublics cannot generate significant policy changes on their own, but can only help trigger changes in specific, rare configurations. It also argues that expectations for minipublics’ influence on public decisions should not come from the minipublics themselves, but from the decision makers and how they engage with the results. For a lack of policy influence may still have important political influence and improve democracy, while a large policy influence may undermine the legitimacy of public decisions. In conclusion, the thesis reflects on the capacity of minipublics to deliver. It warns against creating a “minipublic bubble” if we do not carefully evaluate minipublics’ genuine contributions to solve the crisis of democracy. To unleash the great democratic potential of minipublics, it calls for the development of a problem-based approach to their conception and for the implementation of fewer but grander minipublics. (POLS - Sciences politiques et sociales) -- UCL, 2023