Presidential Coattails versus The Median Voter: Senator Selection in US Elections⇤

We show that senators elected in presidential elections are more ideologi-cally extreme than in midterm elections. This finding is in contrast to the lit-erature suggesting that voters in presidential elections are more ideologically moderate than voters in midterm elections. To explain this incongruence, we propose a theory of spillover effects in which party labels enable voters to up-date their beliefs about candidates across contemporaneous races for office: unexpected support for a candidate in one race carries marginal candidates from the same party in other races. Our theory implies that presidential coat-tails may skew representative government away from the median-voter ideal. ⇤This paper is based on our doctoral thesis. We received many helpful comments from colleagues and seminar and conference participants. We are particularly grateful to our advisors David Austen