Snow is a lot like some of the nastier Roman emperors (Panem comes from the old phrase 'panem et circenses', bread and circuses, from the Roman empire). He rose to power by poisoning his rivals (the reason his mouth is always bleeding is because he poisoned himself to throw off suspicion, then took an imperfect antidote). He is intent on keeping power any way he can, and in a large part rules by terror. Thanks to technology, he has a wide-ranging personal reach, unlike the ancient Roman emperors, who largely couldn't be there to oversee things personally due to the slowness of communication and travel.
