Overvoting and representation: an examination of overvoted presidential ballots in Broward and Miami-Dade counties

Abstract

The closeness of the 2000 presidential election, especially in the state of Florida, has drawn attention to the importance of voting anomalies caused by ballot design, voting technology, and voter errors. In this paper we focus on a particular type of voter error: casting multiple votes for president on a single ballot. Ballots cast in this way are said to contain presidential overvotes, and we examine overvoting patterns in Broward and Miami-Dade Counties, two large and prominent counties in Florida. Using a dataset which contains electronic images of all ballots cast in these counties for the 2000 election, we identify several definitive patterns among overvoted ballots. First, we show that ballots with overvotes on non-presidential races were more likely to contain presidential overvotes compared to ballots with no overvotes elsewhere. Second, we show that ballots with presidential overvotes appear to have been cast by Democratically-inclined individuals and that Al Gore, the Democratic presidential candidate in 2000, appears on a disproportionate number of these ballots. Third and finally, we show that Broward and Miami-Dade precincts with large numbers of blacks, Hispanics, and registered Democrats tended to have high presidential overvoting rates. Overall, the evidence we present implies that a disproportionate fraction of the presidential overvotes cast in Broward and Miami-Dade Counties in the 2000 election were produced by Democrats and this diminished the vote total of Al Gore.