The knowledge gap hypothesis holds that when new information enters a social system via a mass media campaign, it is likely to exacerbate underlying inequalities in previously held information. Specifically, while people from all strata may learn new information as a result of a mass media campaign, those with higher levels of education are likely to learn more than those with low levels of education, and the informational gap between the two groups will expand. Though this hypothesis has received widespread attention in other disciplines, it has attracted relatively little attention in political science. Using data from the National Election Studies, this article investigates how well the knowledge gap hypothesis describes information acquisition in presidential campaigns from 1976 to 1996. The results of the analysis show that knowledge gaps do not always grow over the course of presidential campaigns and that some events, such as debates, may actually reduce the level of information inequality in the electorate.