I haven’t played Suzerain, but if you’re interested in political simulations, I would definitely recommend Autumn Chen’s Social Democracy: An Alternate History, which is a game where you play as the Social Democratic Party in 1930s Germany and try to prevent the Nazis from rising to power. You get to vote on policies and so on and see what happens. Very difficult but fun. There’s a large community on the fanmade Reddit forum and fanmade Discord server, and there are even full-on conversion mods like Biennio Rosso: An Alternate History, a fanmade mod about 1930s Italy. I haven’t played that one.
The game has a sequel called Social Democracy: Petrograd 1917, which is about the 1910s in Russia. I haven’t played that one either, but I think it’s not completely finished compared to the original. I would play Social Democracy: An Alternate History first. I will warn you that there’s a fair amount of reading you’ll have to do about the political system of 1930s Germany before you can really get started in Social Democracy, however.
I haven’t played too many political simulation games besides that one, at least out of the games I’ve enjoyed. I can’t think of many IF games that let you decide on political policies/ideologies in a way that affects the narrative, like Disco Elysium does. But I could be proven wrong, if someone else has their own recommendations for games like that.
You may also enjoy Thousand Lives, which is about the life of a woman in communist Poland. I think there are certain points where she can align herself with or against the communist government. But the game has a feature where you have to play it via email, can only make one choice a day, and need to wait for results to get emailed to you the next day. That prevented me from finishing it, since I’m terrible about checking my email in a timely manner, and if you wait too long, your email gets cleared from the database and you have to restart.
I might be able to give more recommendations if you added more details on what exactly you liked about those two games. Was it the politics, the history, the simulation/management, or something else?
Edit to add: If you just want a good, long, detailed text game to dive into that has really in-depth mechanics, I think you can’t go wrong with Trigaea. It’s an extremely long science fiction RPG made in Twine, around 12 hours long. I never finished that one either, because it takes so long and I gave up on my existing run, but it’s worth checking out at least.