Presidential Coattails and Midterm Losses in State Legislative Elections

The president's party consistently loses partisan control of state legislatures in midterm elections, a pattern similar to the loss of seats in the U.S. House of Representatives in midterms. This study examines presidential coattails as a possible explanation of these losses. Aggregate state legislative election outcomes between 1944 and 1984 in 41 states are examined. The analysis indicates that the president's party gains seats in presidential elections in proportion to the presidential vote in a state, and subsequently loses seats in midterm elections also in proportion to the prior presidential vote in the state. The presidential coattail and the midterm repercussion effects are evident even when gubernatorial coattail effects are introduced, but are fairly modest in states lacking competitive parties.