Candidate debates have a rich history and remain integral to contemporary campaign strategy. There is, however, little evidence that they affect the behavior of voters or politicians. The scarcity of political information in the developing world offers an attractive testing ground. Using experimental variation in Sierra Leone, we find that public debate screenings build political knowledge that changes the way people vote, which induces a campaign expenditure response by candidates and fosters accountability pressure over the spending of elected officials. Results show how political communication can trigger a chain of events that begins with voters and ultimately influences policy.