This is the first comparative study of the relationship between social movements and citizenship rights. It identifies the main connections made between collective action and individual rights, in theory and history, and tests them in the context of modern authoritarian regimes. It does so by measuring both social mobilization and the presence of rights over time, and by analysing their mutual impact statistically - both within and across national cases. The results create a new perspective on democratic struggles in authoritarian conditions, and on processes of democratic transition. The argument is mainly developed through reference to periods of authoritarian rule in Brazil, Chile, Mexico, and Spain. Measuring mobilization and rights provides a comparative description of their forms and fluctuations, just as the statistical results promote a comparative analysis of their influence and interactions. The study uses statistical techniques, but employs them to illuminate historical processes. In sum, its quantitative methods work to enhance the qualitative inquiry, and together they come to constitute a robust defence of democracy as the direct result of collective struggles for individual rights.