One thing you will be doing when writing Science Fiction is creating governments, something that I think is not done as well as it could be. Often writers just take current governments, scale them up then transplant them. This I think is a wasted opportunity.
One lesson that history teaches is that when a people are writing a constitution, and deciding what basic shape their society should take it is almost certainly going to be reactionary. People are going to see the problems they had with the previous government and want to avoid them. The entire US Bill of Rights is written in this way, each one is something that the British did that the colonies did not like and did not want to happen ever again.
That in fact was why the US’s first constitution, the Articles of Confederation, gave the federal government almost no power. It could not even tax, the only source of income it had was from selling land it owned.
To understand the reasoning for the new government all you have to understand is what the sentiment is for the old one. This is why I say that government structures are reactionary, they almost always reflect what the people don’t want to see again.
The point of the post is this; If a people were starting a colony and were mostly happy where they were from I would expect to see them create a government similar to their home. However the odds are they would not be, you don’t become a colonist if you’re happy and content with life were you were born. If your leaving everything you know you have to have a good reason, it could be anything from too much religious freedom (pilgrims) to wanting more upward mobility (much of the early American immigrants) to almost anything else.
So when your talking about setting up a new government think about what problems the first generation had with its previous government, think about what they disliked and why they left. This is where you can get a lot of drama and some real world building.
Religious colonies are nothing new, all you have to do is open a history book to see examples, I think going in directions that are new would be more interesting. Even within the confines of a representative republic there is a lot of room for new and interesting governments.
Maybe a nation was founded by people who hate large corporations and don’t want them to form. How would they do that? And just as importantly what problems would that cause? How do they deal with colonies from other systems?
Or a colony was founded by the super rich who want a place away from taxes and oversight. They might create a system where bills are voted on by money, or your vote counts for more if your richer.
All government systems are flawed, no matter the one in place a large number of people will dislike it. And never forget your a writer, you want problems, even small ones can be useful.