Replication data for: No More Wilder Effect, Never a Whitman Effect: When and Why Polls Mislead about Black and Female Candidates

The 2008 election renewed interest in the Wilder or Bradley effect, the gap between the share of survey respondents expressing support for a candidate and the candidate’s vote share. Using new data from 180 gubernatorial and Senate elections from 1989 to 2006, this paper presents the first large-sample test of the Wilder effect. It demonstrates a significant Wilder effect only through the early 1990s, when Wilder himself was Governor of Virginia. Evidence from the 2008 presidential election reinforces this claim. Although the same mechanisms could affect female candidates, this paper finds no such effect at any point in time. It also shows how polls’ over-estimation of front-runners’ support can exaggerate estimates of the Wilder effect. Together, these results accord with theories emphasizing how short-term changes in the political context influence the role of race in statewide elections. The Wilder effect is the product of racial attitudes in specific political contexts, not a more general response to under-represented groups.