There's a lot of talk of "dueling ideologies" here. But how do you translate that into game mechanics? So far as I can tell every country is just as Machiavellian as ever, ideological differences being for nothing more than popularity contests for democracies, sheer economic/diplomatic (power) self interest for plutocracies (E.G. the UAE), and sheering into narcissistic lunacy for autocracies.
Thus maybe the three "modern" ideologies should be those 3 (fascism and communism all but died off after all). Democratic ideology tree could have a lot of bonuses and the most potential for generating resources and winning, but be heavily dependent on happiness. I.E. If your Civ trades a lot of culture with another civ, then your pop could have a "positive" view of that civ, and if you do something bad diplomatically to them you lose happiness
. Suddenly just like modern democracies the player has to pay attention to what makes their citizens happy or not all the time.
The plutocracy branch could offer options that have money give happiness bonuses, or have luxuries replace dissatisfaction or etc. The more money you have, the less you have to worry about what you're doing diplomatically, and of course there's the "police station" building or etc. that keeps an unhappy citizen or two working, and keeps rebellions at bay. Just keep the money going, and some police stations and policies around, and you're mostly good! This branch would be the "balance", it's less complicated than the Democracy branch to keep production up, and that gives you more freedom to switch up diplomacy how you see fit, but it isn't entirely free of tradeoffs.
The autocracy branch could just offer heavy handed repression. Internet censorship policies, "secret police" units, all stuff that forces even unhappy citizens to keep working, counters any rebellions that are brewing, and manipulates what civs they like and don't like directly. Now you the player doesn't have to care about your citizens happiness, you're the one in charge! This branch doesn't give you any production bonuses, but you have great autonomy in how you want to do diplomacy and deploy resources and etc. Go ahead, declare a surprise war against that neighbor that has a huge culture bonus versus you and is causing your citizens to be unhappy and consider rebelling, with autocracy you can afford it.