(Before I even begin, this is all apropos of the fact that I’m rereading a few of the older books in the Expanded Universe)
It’s basically an article of faith among Star Wars fans that the Galactic Empire — as depicted in the original trilogy — is purely evil and the Alliance to Restore the Republic (or Rebel Alliance for short) is unambiguously good. And there’s a lot of solid evidence for that assessment. On-screen, we’ve seen the Empire wipe out the Jedi, destroy entire worlds, enslave peaceful peoples, and declare that their ultimate aim is perpetual rule through fear of force alone. Indeed, the Empire is so evil that it actively rewards cruelty: Grand Moff Tarkin — the commanding officer of the first Death Star — was awarded his title after slaughtering hundreds of anti-Imperial protesters in cold blood.
All of that said, I’m not so certain that the operating philosophy behind the Galactic Empire — that despotism is necessary to maintaining the peaceful cohesion of a galaxy-spanning empire — is entirely wrong. Especially since we have enough examples of republican forms of galactic government to know that the alternative isn’t that much better. The previous galaxy-spanning political unit — the Galactic Republic — collapsed largely because it was too large to be effective. The Republic didn’t even possess the strength or legitimacy to handle a trade dispute on a minor core world, much less an existential threat like the Clone Wars. On the other end of the timeline is the successor regime to the Rebel Alliance, the New Republic. The New Republic was, like its namesake, a loose confederation of worlds united by common economic ties and a representative body. It maintained a large military, for the purpose of defense and peacekeeping, and was firmly committed to respecting the rights of sentient beings. It was also a complete failure.
For the full 23 years of its existence, the New Republic was beset by division and problems of legitimacy. Consensus was habitually hard to come by, even in times — like the Thrawn crisis — when it was absolutely necessary. Indeed, the New Republic fell precisely because it couldn’t muster the cohesion or will to defend itself against the extra-galactic Yuuzhan Vong, despite possessing the combined resources of an entire galaxy.
Now, to me at least, this suggests that a single galactic, representative governing body — no matter how well intentioned — is simply incapable of dealing with such an overwhelming diversity of cultures, viewpoints and agendas (remember, we’re talking about trillions of people and tens of thousands of different lifeforms). If you’re committed to something vaguely democratic, the only real option is a galactic confederation — not dissimilar to the Federation in the Star Trek continuity — where each member planet or sector has extremely limited ties to a central “governing” body of limited authority. Of course, there are real threats from within and outside the galaxy, and there is a real need for a centralized authority, if only for collective defense. In which case, it seems that the only way you could have effectivecollective defense is by forcing each member planet to provide for a common army and navy, which requires enough force for coercion, which in this context can only be successful if the regime has little respect for rights: i.e. the Empire.
Palpatine was incredibly brutal and evil, but he also understood — correctly — that successful galactic dominion requires the kind of cruelty and brute force that we see on display in the movies. Otherwise the whole thing will collapse into petty-infighting and jealousy.