Published ; This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record. ; Political misperceptions can distort public debate and undermine people's ability to form meaningful opinions. Why do people often hold these false or unsupported beliefs, and why is it sometimes so difficult to convince them otherwise? We argue that political misperceptions are typically rooted in directionally motivated reasoning, which limits the effectiveness of corrective information about controversial issues and political figures. We discuss factors known to affect the prevalence of directionally motivated reasoning and assess strategies for accurately measuring misperceptions in surveys. Finally, we address the normative implications of misperceptions for democracy and suggest important topics for future research. ; This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (Grant Agreement No. 682758). We thank Adam Berinsky, Daniel Diermeier, Jamie Druckman, Howie Lavine, Ben Page, Ethan Porter, Gaurav Sood, Joe Uscinski, attendees at the University of Michigan conference on How We Can Improve Health Science Communication, and especially the anonymous reviewers for useful suggestions and feedback. All remaining errors are, of course, our own. Correspondence concerning this article should be addressed to Brendan Nyhan, Dartmouth College, Department of Government, 3 Tuck Mall, Hanover, NH 03755. E-mail: brendan.j.nyhan@dartmouth.edu