We investigated how political party affiliation and political attitudes modulate neural activity while viewing faces of presidential candidates. Ten registered Democrats and 10 registered Republicans were scanned in an event-related functional MRI paradigm while viewing pictures of the faces of George Bush, John Kerry, and Ralph Nader during the 2004 United States presidential campaign. We found that compared with viewing one's own candidate, viewing the candidate from the opposing political party produced signal changes in cognitive control circuitry in the dorsolateral prefrontal cortex and anterior cingulate, as well as in emotional regions such as the insula and anterior temporal poles. BOLD signal in these regions correlated with subjects' self-reported ratings of how they felt emotionally about the candidates. These data suggest that brain activity when viewing a politician's face is affected by the political allegiance of the viewer and that people regulate their emotional reactions to opposing candidates by activating cognitive control networks.