In answering this question, pay attention to the ways in which both Machiavelli and Hobbes in the early modern phase of Western political thought shift the focus from politics as the attainment  and mainitenance of harmonious justice for the common good to the attainment and maintenance of  power, by aligning the interests of the ruled with that of the ruler. What is the difference and how does "normalizing" the concept of rational self-interest change the dynamic from the one to the other?  You do not have to spend a lot of time citing Plato, but you should build your understandiing of Machiavelli and Hobbes on your understanding of Plato.  You should cite liberally from relevant passages in Machiavelli and Hobbes.  Pay particular attention to Chapter 15 of The Prince, and Chapters 13-15 of Hobbes’ Leviathian (though, realistically, you should be using whatever material you find relevant from either work.)