One Strike and You're Out: The Effects of the Master Lever on Senators' Positions

This paper accounts for the effects of the master lever (ML), aka the straight-ticket voting option, on elected US senators from 1960 till 2012. The ML, still present in some states, allows voters to select a specific party for all elections listed on a ballot, as opposed to filling out each office individually. Introducing it leads to an increase in the number of partisan votes, and thus changes the groups of voters targeted by parties and shifts the positions of senatorial candidates. Theoretically, we examine this change in tradeoffs by building a model of pre-election competition. Empirically, we use a triple-difference estimator to account for selection into treatment and find that, controlling for party trends, the ML has led to a right-wing shift of senatorial positions; an effect that is larger for the Republican party. We use the theory to explain how the political climate, as observed in the data, has implied the specific result.