The Effect of Electronic Voting Machines on Change in Support for Bush in the 2004 Florida Elections
- Irregularities associated with electronic voting machines may have awarded 130,000 excess votes or more to President George W. Bush in Florida.
-Compared to counties with paper ballots, counties with electronic voting machines were significantly more likely to show increases in support for President Bush between 2000 and 2004. This effect cannot be explained by differences between counties in income, number of voters, change in voter turnout, or size of Hispanic/Latino population.
-In Broward County alone, President Bush appears to have received approximately 72,000 excess votes.
-We can be 99.9% sure that these effects are not attributable to chance.
Because many factors impact voting results, statistical tools are necessary to see the effect of touch-screen voting. Multiple regression analysis is a statistical technique widely used in the social and physical sciences to distinguish the individual effects of many variables.
This multiple-regression analysis takes account of the following variables by county:
- number of voters
- median income
- Hispanic population
- change in voter turnout between 2000 and 2004
- support for President Bush in 2000 election
- support for Dole in 1996 election
When one controls for these factors, the association between electronic voting and increased support for President Bush is impossible to overlook. The data show with 99.0% certainty that a county’s use of electronic voting is associated with a disproportionate increase in votes for President Bush.
The data used in this study come from CNN.com, the 2000 US Census, the Florida Department of State, and the Verified Voting Foundation – all publicly available sources. This study was carried out by a group of doctoral students in the UC Berkeley sociology department in collaboration with Professor Michael Hout, a member of the National Academy of Sciences and the UC Berkeley Survey Research Center.