An empirical finding by Gaspar, Jaramillo and Wingender (2016) shows that once countries cross a tax-to-GDP threshold of around 123⁄4 percent, real GDP per capita increases sharply and in a sustained manner over the following decade. In this paper, we attempt via four case studies—Spain, China, Colombia, and Nigeria—to illustrate that the improvements in tax capacity have been part of a deeper process of state capacity building. We discuss the political conditions that supported tax capacity building, highlighting three important political ingredients: constitutive institutions, inclusive politics and credible leadership.