This study examines the dynamic, real-time interplay between the emotional content of political television ads and individuals’ political attitudes during ad processing based upon the Dynamic Motivational Activation (DMA) theoretical framework. Time-series cross-sectional models were developed to test the effects of three motivational inputs of emotional ads (arousing content, positivity, and negativity) and viewers’ evaluation of the featured candidates on four psychophysiological responses (heart rate, skin conductance level, corrugator electromyography, and zygomatic electromyography). As predicted by the DMA, physiological responses during ad viewing were affected by their own first- and second-order dynamic system feedback effects. These results not only support the predicted dynamic nature of the physiological system but also help disentangle message effects from the moderating and accumulating effects of the physiological system itself. Also as predicted, message motivational inputs interacted with viewers’ political attitudes to determine psychophysiological responses to the ads. Supporters of opposing political candidates showed cardiac-somatic response patterns indicative of disparate attention to the advertised information. Attentional selectivity can be a critical component in determining how information processing influences campaign message reception and effects.