There is one thing that the frivolous writer often gets better than the serious writer with a message.
True, the frivolous writer often uses a lot more monarchies, and is not quite aware of other possibilities. And their character of lowly birth often have an entirely too easy time talking to the king. Even people of quite high birth would have more difficulties getting to the king in reality.
But at least, they aren't out to change the political systems of their world. It's amazing.
If you want to have a revolution in your world, write down on a piece of paper: There Are Arguments Against Democracy.
And then find them out before you write. And use them. And don't make using them proof that a given character is evil.
After all, James Madison pointed out that democracies commonly had short lives and ended very bloodily. Someone who more seriously disproved of that form of government would have more arguments against it.
Not all the characters will, of course. The overwhelming majority, unless you chose your setting very carefully, will not be able to argue for monarchy -- any more than most people can argue for democracy nowadays. They, like us, will just take it for granted.
If you expose them to the concept of democracy, they will not instantly say, "How wonderful!" They are far more likely to say, "How appalling!" They very likely to fight quite hard against the notion -- and in the process, at least some of them will figure out the arguments.
True, the frivolous writer often uses a lot more monarchies, and is not quite aware of other possibilities. And their character of lowly birth often have an entirely too easy time talking to the king. Even people of quite high birth would have more difficulties getting to the king in reality.
But at least, they aren't out to change the political systems of their world. It's amazing.
If you want to have a revolution in your world, write down on a piece of paper: There Are Arguments Against Democracy.
And then find them out before you write. And use them. And don't make using them proof that a given character is evil.
After all, James Madison pointed out that democracies commonly had short lives and ended very bloodily. Someone who more seriously disproved of that form of government would have more arguments against it.
Not all the characters will, of course. The overwhelming majority, unless you chose your setting very carefully, will not be able to argue for monarchy -- any more than most people can argue for democracy nowadays. They, like us, will just take it for granted.
If you expose them to the concept of democracy, they will not instantly say, "How wonderful!" They are far more likely to say, "How appalling!" They very likely to fight quite hard against the notion -- and in the process, at least some of them will figure out the arguments.

Comments
A king will act. Getting a democracy or a republic to do something is hard to do within the confines of 100K novel.
Best overthrow a dictator, rather than a king, one who gained power by illegitimate force. Then you can restore the republic, monarchy, or whatever, which everybody agrees on. You don't have to have dialogues about government forms.
Also, coronations are much more dramatic than elections. 0:)
The song is called "Baby Doll"--it's cute. No YouTube video, but lyrics here
My own impression is that people didn't use to fool around like that. They wouldn't talk about their leaders. Like sensible people, they talked about their rulers.
Using appropriate vocabulary for the (type of) era you're setting your story in is a great way to make it sound more authentic (or to jar a reader terribly, if you don't bother...)
not tonight though
‘Don’t be emperor, then,’ she shot back.
So he gave her a hearing.
As late as the early nineteenth century, access to monarchs (except in Russia, China, and Japan) was not difficult to arrange, provided that one followed reasonable measures of protocol. George III was an approachable chap; he used to take a daily constitutional in the park, at which time anyone who liked could see him, if they were polite about it. Unfortunately he was also a non-stop talker, and it was rare for any of his interlocutors to get a word in edgewise. But then, even his cabinet ministers had that problem.
Of course, George III had the leisure to do that because he was a constitutional monarch and his ministers did the actual job of governing. His last Prime Minister was Lord Liverpool, who during his fifteen years in office wrote tens of thousands of letters in his own hand, answering virtually every letter or petition from the public that came across his desk. The Duke of Wellington ran the War Office on the same lines.
It is sad but true that the average school principal or family physician today is less accessible to the public than the average monarch before the Industrial Revolution. Modern technology has made communications so easy that every person of importance employs a staff of secretaries, receptionists, and personal assistants to prevent communication from happening.
Jonathan Swift had the mathematicians of Laputa followed everywhere by attendants, who flapped their masters on the ear with a bladder to let them know when someone was speaking to them. This characteristic Swiftian touch was offered as evidence of how absent-minded the Laputans were. If Swift had known that within a couple of centuries, men would employ ‘flappers’ not out of absent-mindedness but out of sheer self-importance, and that the flappers would often refuse to flap their employers’ ears — why, he would given up on the human race as a subject beyond the scope of satire, and chucked Gulliver’s Travels in the fire.
Pre-industrial monarchs were also far more vulnerable to assassination than are modern Presidents, etc. (for that matter, the same thing was true of US Presidents before the JFK assassination). They often went about among the people with only a few bodyguards, and no real protection save for luck or their own fighting prowess against anyone determined to kill them and willing to risk probable death in the process. Several were assassinated; many more survived attempts. Elizabeth the Great of England was in particular famed for her coolness (and mercy) in one such situation, in which a deranged old woman attempted to murder her with a horse pistol -- she barely flinched when the pistol misfired at point-blank range, and then insisted that the woman's life be spared.
The first attempt to assassinate a president was on Andrew Jackson, and the man used a gun but got so close that the president was the first one to reach him. And the would-be assassin found that the president carried a good, solid hickory stick.
The writers also tend to omit that there will be protocol at the meeting; the cowherd is not going to to chat with the king like they were long lost buddies. (Samuel Johnson, at one point, was listening to Boswell talk about great people who had lost touch with their old friends, and his rejoiner was that their old friends had forgotten that, after all, these people were great now and they couldn't act as if they were all schoolboys together still.)
You meet -- the walk is a lovely example because it is not part of the court formalities. Or, OTOH, you get smuggled up the back stairway to the cabinet, so that the high nobles can't see you go in.
The entire set-up depended on the sultan being willing to let another woman sleep in his bedroom.
Also remember that the majority of revolutions have promised greater democracy, but either not delivered it (New Boss, Same as the Old Boss, as with most Latin American revolutions) or delivered something worse than the Old Regime (French Revolution, Russian Revolution, Nazi Revolution, Chinese Revolution, etc.). Just because someone claims he is for "democracy" does not make him the good guy.
If you expose them to the concept of democracy, they will not instantly say, "How wonderful!" They are far more likely to say, "How appalling!" They very likely to fight quite hard against the notion -- and in the process, at least some of them will figure out the arguments.
One big problem with democracy in a pre-industrial setting is that the masses will be very poorly educated by modern standards, unless this is a highly mercantile city-state (Athens, Rome). This means that most of the people won't have the information needed to make intelligent choices between leaders, and are very likely to fall victim to tyrants posing as "men of the people."
OTOH, I don't think that education has greatly increased people's ability to "make intelligent choices between leaders."
It was worse in pre-industrial times, because a pre-industrial society generally depended upon a very large percentage of the population engaging in subsistence farming to support a very small percentage who had the leisure to learn to read and write and to use these skills in political debate. Our present technological civilization is probably the most literate and well-educated that ever was -- which should make you realize just how ignorant the masses were in earlier days!
People who work on re-entactments, who get to stop and explain to the curious tourists what they are doing instead of doing it all day, who do not actually have to do enough to keep alive -- still find themselves absolutely exhausted by it.
And they're eating a modern diet. With enough calories.
You only have twenty-four hours in a day. You have to pick and chose what you get informed about.
"The problem with socialism is that it takes up too many evenings" Oscar Wilde