Spending way to much time considering this question, here is my first stab:
#1 It is autocratic – Emperor Palpatine takes over from the senate in a direct power play that alludes to Emperor Augustus taking over the Roman Republic. Many autocratic states have been in existence without being evil themselves. This only sets up that the Emperor has unrestricted power. Whether he uses it for good or evil is his, and only his, choice.
#2 it is militaristic - Emperor Augustus is purported with having said “I found Rome a city of bricks and left it a city of marble.” He used his power to improve the city (at least aesthetically) and put Romans on the bread doles to work in public works. Emperor Palpatine can really only be shown to have organized an overpowering military for a government that did not need a galactic military. He is reminiscent of Hitler in that he puts the populace to work building a strong military that he uses to control the populace. The only people who oppose the Empire are citizens of the Empire. Mostly everyone else keeps their heads down and tries to avoid any contact with the Empire.
#3 it is racist – In contrast to the Galactic Empire which was shown to be richly diverse. The Galactic Empire, to borrow from Star Trek, is a “homo-sapiens only club” in the movies. Sure, Luke is considering joining the Academy; he fits into their uniform. On board the death star, star destroyers, and TIE fighters and shuttles, you’ll find only humans and mechanical slaves. Bespin, Tatooine, Yavin, the Jedi Council, etc. are all culturally and racially diverse. For the Empire, anyone outside the club deserves no rights, as can be seen in the “rebel scum” and “Where are you taking this THING?” comments. The only role that nonhumans have in the Empire are as collaborators, spies, and bounty hunters.
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Opening in Gunboat as Russia
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