Looking for two-sided coattail effects: Integrated parties and multilevel elections in the U.S.

In the context of the American federalism, integrated parties provide the necessary coordination mechanism for state and federal politicians to be electorally successful. This argument rests on the assumption that voters are able to observe the benefits of voting a straight ticket. We test this individual level explanation by using the CCES data. Moreover, at the aggregate level, we measure the so-called 'two-sided' coattail effects in concurrent multilevel elections in the U.S. since 1960. By using a simultaneous equation model, we estimate the reciprocal relationship between presidential and gubernatorial vote shares at the state level. While we find no consistent presidential coattails, we reveal robust and significant gubernatorial coattail effects on state-level presidential vote, underscoring the role of multilevel forces within parties in democratic federations.