The aged remain one of the few vulnerable groups without formalized protection in their own covenant. Attempts to secure a UN declaration on older persons’ rights in 1948, 1991, and 1999 failed to gain traction, but the most recent attempt to launch a campaign has garnered support from civil society and a large group of states. What explains the traction of the rights frame during the most recent campaign? Through interviews, observation, and qualitative analysis of key documents, I argue that norm diffusion from Latin America to the international level and from the debate and passage of the UN Convention on the Rights of Persons with Disabilities in 2006 drove the timing and, to some degree, the salience, of the contemporary CROP campaign and that states’ interests and incentives, which have shifted as population ageing has intensified, mainly explain their support or resistance. The findings increase our understanding of agenda-setting in social movements and at the UN, and of the broader political implications of global population ageing. The findings also indicate that the proposed convention faces significant hurdles and is unlikely to be passed in the near future.