And now you have me thinking of the Iron Born from A Song of Ice and Fire...-Neo-Medieval Piracy as usual, is a case of splitting the difference--in this case the Golden Age of Piracy and the Viking Age. (The Vikings also had a system that resembled democracy as much as not.) As it is, our image of the Pirate has been Hollywooded up, (Many were not white, nobody really buried treasure) so it helps to go back to the source. Also, I can imagine a lot of them being Cocaine addicts.
That and Pirate Shield Maidens.
-Totalitarian governments already exist in the Hydraulic Empires. Invoking Fascism specifically would not make sense as it would be loaded (People don't want to use the term King for their feudal states) and fairly redundant. Society is already a militaristic throwback, without the industrial infrastructure that distinguishes fascism.
As for Communism, likewise, I think any ecclesiastical fiefdoms or nomadic tribes would effectively accomplish a lot of Communist goals, but without the polarizing labels, or the mass scale.
You still have plenty of room for regional national identities, cultures and governments."Renaissance Level" would be around the the Eastern Seaboard and a few other places, but once you start getting to the 1600's, you get to technology and culture that has already existed in the Americas, and then you don't really have the premise anymore.
Cowboy cossacks, French styled nobility in the deep South, etc.