Competition in political debate is not always sufficient to neutralize the effects of political rhetoric on public opinion. Yet little is known about the factors that shape the persuasiveness of political arguments. In this article, I consider whether cognitive biases influence the perceived strength of political arguments, making some arguments more persuasive than others. Lessons from neurobiology and recent political psychology research on emotion lead to the expectation that individuals are more likely to be persuaded by political arguments that evoke loss aversion via a fearful response—even in the face of a counterargument. Evidence from two experiments corroborates this expectation. I consider the normative implications of these empirical findings and potential avenues for future research.