The nationalization of electoral cycles in the United States: a wavelet analysis

We take a new look at electoral sectionalism and dynamic nationalization in presidential elections. We treat this problem as one of synchronism of electoral cycles, which we estimate by using wavelets. After providing a self-contained introduction to wavelet analysis, we use it to assess the degree and the dynamics of electoral synchronization in the United States. We determine clusters of states where electoral swings have been more and less in sync with each other and with the national cycle. Then, we analyze how the degree of synchronism of electoral cycles has changed through time, answering questions as to when, to what extent, and where has a tendency towards a “universality of political trends” in presidential elections been more strongly felt. We present evidence strongly in favor of an increase in the dynamic nationalization of presidential elections taking place since the 1950s, largely associated with a convergence in most (but not all) Southern states.