We provide a game‐theoretical model of manipulative election campaigns with two political candidates and a Bayesian voter. The latter is uncertain about how good the candidates are. Candidates take unobservable, costly actions to manipulate voter's opinion about their positions. We show that if the candidates differ in campaigning efficiency, and the voter receives the biased campaign messages with some noise, then the cost‐efficient candidate can win the election with higher probability than her opponent even when she is ex‐post an inferior choice for the voter. Our paper offers a novel informational justification for imposing limits on campaign spending and encouraging diversity in the supply of political information.