Supporters of touch-screen voting claim it is a highly reliable voting technology, while a growing number of critics argue that paperless electronic voting systems are vulnerable to fraud. In this paper we use county-level data on voting technologies in the 2000 and 2004 presidential elections to test whether voting technology affects electoral outcomes. We first show that there is a positive correlation between use of touch-screen voting and the level of electoral support for George Bush. This is true in models that compare the 2000-2004 changes in vote shares between adopting and non-adopting counties within a state, after controlling for income, demographic composition, and other factors. Although small, the effect could have been large enough to influence the final results in some closely contested states.