How does political preference affect categorization in the political domain? Eight studies demonstrate that people on both ends of the political spectrum—strong Republicans and strong Democrats—form simpler and more clustered categories of political stimuli than do moderates and neutrals. This pattern was obtained regardless of whether stimuli were politicians (Study 1), social groups (Study 2), or newspapers (Study 3). Furthermore, both strong Republicans and strong Democrats were more likely to make inferences about the world based on their clustered categorization. This was found for estimating the likelihood that geographical location determines voting (Study 4), that political preference determines personal taste (Study 5), and that social relationships determine political preference (Study 6). The effect is amplified if political ideology is salient (Study 7) and remains after controlling for differences in political sophistication (Study 8). The political domain appears simpler to the politically extreme than to political moderates.