This paper proposes a statistical analysis of institutional power of national institutions for the promotion and protection of human rights (NHRI). It draws on the literature of cross-border institutional diffusion and builds on an original data set. The focus of the statistical analysis is on the role that membership in regional and international organizations plays in the power of the institutions mandated to promote and protect human rights at the domestic level. The analysis builds on a relatively small number of prior studies of national human rights institutions accredited by the International Coordinating Committee at the Office of the United Nations High Commissioner for Human Rights and broadens the scope of the analysis to include other non-accredited independent institutions mandated through national constitutions or domestic secondary law to handle human rights cases.