Indeed, there aren't many non-infantile dictators. Plato's Ring of Gyges story explains why that's so. The ring gives its wearer the power of invisibility. So the question is whether we refrain from committing crimes only because we're afraid of getting caught and punished. If we completely remove that possibility, such as by giving us the power of invisibility--or by making us dictator with absolute power over others--would any of us still refrain from committing crimes out of some abstract or conditioned commitment to morality?
I have an article coming out soon on a related question: Why is murder abhorrent? That is, can we still justify our abhorrence of murder? Is the cause just social conditioning that can be undone?