Accusations of entrenched political partisanship have been launched against both conservatives and liberals. But is feeling superior about one's beliefs a partisan issue? Two competing hypotheses exist: the rigidity-of-the-right hypothesis (i.e., conservatives are dogmatic) and the ideological-extremism hypothesis (i.e., extreme views on both sides predict dogmatism). We measured 527 Americans' attitudes about nine contentious political issues, the degree to which they thought their beliefs were superior to other people's, and their level of dogmatism. Dogmatism was higher for people endorsing conservative views than for people endorsing liberal views, which replicates the rigidity-of-the-right hypothesis. However, curvilinear effects of ideological attitude on belief superiority (i.e., belief that one's position is more correct than another's) supported the ideological-extremism hypothesis. Furthermore, responses reflecting the greatest belief superiority were obtained on conservative attitudes for three issues and liberal attitudes for another three issues. These findings capture nuances in the relationship between political beliefs and attitude entrenchment that have not been revealed previously.