We explore how the uniformity of electoral swings in the district vote within countries is affected by the level of economic and political decentralization. We rely on district-level data from OECD countries in two consecutive elections before and after the Great Recession to show that as regional governments exert more influence over the central government, districts deviate less from the overall pattern of change in support of the national incumbent party. The causal mechanism accounting for the effect of decentralization on dynamic nationalization is examined with individual panel data from national elections in Canada and Spain.