Previous research has noted one's knowledge of and attitudes toward the theory of evolution is negatively predicted by one's political ideology, specifically how conservative the individual identifies, and positively predicted by one's level rational thinking. The present research expands on this past research by examining the roles of political conservatism and rational thinking in predicting one's reported relevance of evolutionary theory in a multi‐study design. In Study 1, a sample of undergraduate college students (N = 198) completed a survey with measures of conservatism, rational and intuitive thinking styles, including both engagement and ability, and attitudes toward the relevance of evolutionary theory. A multiple mediator model revealed that conservatism was a negative predictor rational engagement, rational engagement was a positive predictor of relevance of evolution, and the indirect effect of conservatism on relevance of evolution through rational engagement was significant. In Study 2, a new sample of college students (N = 146) completed an experiment where rational engagement was manipulated. Conservatism negatively predicted relevance of evolution for individuals who were not primed to engage in rational thought and were below average in rational ability. Conversely, conservatism was not a significant predictor of relevance of evolution for individuals who were primed to engage in rational thought, and who had below average rational ability scores. These results suggest that when individuals are lower in rational ability, priming for rational engagement may be effective at buffering the effect of conservatism on one's reported relevance of evolution. Thus, examining additional procedures for increasing one's rational engagement may be useful for educators and researchers interested in reducing the effects of political ideology on one's knowledge of and attitudes toward evolution.