Every vote creates winners and losers, opening a satisfaction gap between the two. At a time when concerns are high for democracy, we do not know what exactly leaves substantial proportions of voters—losers—dissatisfied with the system. This paper provides causal evidence for the cognitive dissonance theory, which points at unfulfilled winning expectations. With a difference-in-differences design around the Brexit referendum, it finds that the result caused an additional 3% decrease in the Remainers’ satisfaction if they were expecting to win the vote. The gap grows with the strength of expectations, and the losers to whom the result came as a complete surprise experienced almost a three times larger decrease in satisfaction, compared to the Remainers who were sure they would lose. If winning expectations affect how dissatisfied losers become after votes, then those who set expectations about voting outcomes have responsibilities for the stability of democracy.