While in recent decades developing countries have achieved significant improvements in well-being, disparities within countries persist. Focusing on municipalities in which health services are decentralized and patronage is prevalent, we argue that a little-studied factor, the alignment between mayors and governors, plays an important role in explaining differences in infant mortality rates. In the context of widespread clientelism, lack of alignment deprives mayors of substantial discretionary resources. This generates incentives for nonaligned mayors to focus on improving decentralized social services under their control to cultivate voter support, producing better welfare outcomes associated with these services. Employing an original dataset of metropolitan municipalities in Buenos Aires, Argentina, between 1991 and 2018, we find that mayoral alignment is associated with higher infant mortality, a critical metric of well-being, and with lower levels of health service provision. Local health services in turn reduce infant mortality rates in our data. These results are robust when we control for relevant socioeconomic and political factors, such as electoral competition, protest, and the presence of the state in slums, where health risks are higher.