History offers many examples of dictators who worsened their behavior significantly over time (like Zimbabwe’s Robert Mugabe), while there are also cases of dictators who have displayed remarkable improvements (like Jerry Rawlings of Ghana). We show that such mutations can result from rational behavior when the dictator’s flow use of repression is complementary to his accumulated stock of wrongdoings. This complementarity gives rise to two steady states (one where repression is low and one where repression is high) and implies that any individual rising to power in this setup has the potential to end up as either a moderate leader, or as a dreaded tyrant. Our model shows that dictators are more likely to derail with higher levels of divertible funds available, for example stemming from fungible aid inflows or from the exploitation of natural resources.