This research addressed theoretical approaches in political science arguing that the American electorate is either poorly informed or dependent on party label cues, by assessing performance on political judgment tasks when party label information is missing. The research materials were created from the results of a national opinion survey held during a national election. The experiments themselves were run on nationally representative samples of adults, identified from another national electoral survey. Participants saw profiles of simulated individuals, including information about demographics and issue positions, but omitting party labels. In Experiment 1, participants successfully judged the likelihood of party membership based on the profiles. In Experiment 2, participants successfully voted based on their party interests. The results were mediated by participants' political knowledge. Conclusions are drawn with respect to theories from political science and issues in cognitive science regarding categorization and reasoning.