The recording of event-related potentials (ERPs) in the brain has allowed for a better understanding of human sensory and cognitive processing. This technique may also prove useful in studying implicit social attitudes and their effects on information processing. Here, ERPs were used in a study of “hot cognition” in the context of political concepts. Hot cognition, as applied to the political domain, posits that all sociopolitical concepts that have been evaluated in the past are affectively charged, and that this affective charge is automatically activated from long-term memory within milliseconds of presentation of the political stimulus. During an evaluative priming task, ERP recordings showed that affectively incongruent prime/target pairs elicited an enhanced negativity with a peak latency of about 400 milliseconds relative to affectively congruent prime/target pairs. These differences suggest that automatic, implicit evaluations were made in response to strongly positive and negative political stimuli, and that these evaluations affected the subsequent processing of a high-valence adjective. Therefore, it appears that the emotional valence of a political prime is stored along with the concept itself, and that an affective response becomes active upon mere exposure to the political stimulus.