Are anti‐establishment mass media really useful in preventing politicians from behaving dishonestly? This paper models the direction of media bias, and shows that the probability of a dishonest action by an incumbent is higher (than that in the case of no media bias) if and only if the mass media have some degree of “anti‐incumbent” bias (i.e. information favourable to the incumbent is converted into unfavourable news about the incumbent with a positive probability), provided that the incumbent is less likely to be opportunistic than a challenger in the upcoming election. This result holds irrespective of the degree of “pro‐incumbent” bias.