This book provides a comparative analysis of how judgments from the European Court of Human Rights (ECtHR) and the Inter-American Court of Human Rights (IACtHR) affect political participation and electoral justice at the national level. Looking at specific countries, the work analyses the legal impact the implementation of the ECtHR and the IACtHR judgments has, with a specific focus on cases in which the regional court concerned uses the “democratic argument,” that is, an argument related to democracy and political rights. The reasoning is that, although democracy is a much wider concept, judgments concerning violations of political rights and electoral justice provide reliable indicators to assess the status and sustainability of democracy in a State. Moreover, the analysis of the violations of political rights and electoral justice allows an in-depth comparison between the two regional human rights systems. Mindful of the broader scope of the fall-out generated by the non-implementation of judgments, including in socio-economic terms, the book includes a section exploring how judgments issued by the ECtHR and the IACtHR affect voters’ participation in the countries under their jurisdiction. To this end, an original dataset including the 47 Member States of the Council of Europe and the 20 countries which recognised the adjudicatory jurisdiction of the IACtHR is built. Multidisciplinary in aim and scope of analysis, the book will be an invaluable resource for researchers, academics, and policy-makers working in the areas of constitutional law, international human rights law, and political economy.