Ooooh well, this largely depends on how aware are your Pokémon of the scope of what those leaders are doing. Since the once thing about Pokémon perception-wise is that, discounting stuff like psychic perception, empathetic detection, ~*Aura*~ etc, they are also supposed to be far more in-tune with Mother Nature, to the point where wild encounter Diglett can tell you that building a dam is WRONG™.
So if your Pokémon sense at , say, the AU stand-in of Henry Ford or of Henry Kissinger they are probably going to feel meh or even "nice" about them, but if they can sense the effect of their actions at a larger scope, I figure out much of the response will start at the level of "vade retro" / "humanan non grata".
A few things that I feel could be considered as patterns for some sort of global responses.
* You mention that dragons would love authoritarianism, sorry to inform you but nope, since they know there's by their very nature at least one equal to them and the last thing a true dragon would accept is that other dragon can lord over them simply because they think they've got access to a nicer limestone cave. Dragons would probably be all about a mix of socialism and utilitarian autocracy: they serve themselves (and set political boundaries on) on everything they can get their paws on solely on their own effort, and delegate everything else to a designated faction that collects and organizes for their general sense of tribute (ie.: the Pokémon equivalent of a dragon's kobolds in D&D).
* That said, dragons would totally take on some sort of "nationalist autocracy" concept. Unsure of how to even begin building it, but if you can get a human to execute something that gives off that vibe and feels stable enough to last at least one dragon lifetime (150~ years, maybe?), then I'd bet you've got their interest.
* Who would feel more in vibe with authoritarianism in my perception? At a first glance I'd say minor legendaries would: they have the population density / rarity factor for it, and in a Trainerverse already suffer from undue selective pressure from teams of Trainers and from higher-tier Legendaries (or from "trio masters") that would lead them to favour rigid application of measures to secure territory or genetic legacy. We've already been given hints of it in M2 at least.
* I'd feel the Pokémon world would be kind of self-selecting towards the effect of species that have to face a regular phenomenon over their lives at about the same time (eg.: Pokémon who have a relatively static annual migration) prefering democratic leaders, since they would feel such kind of leader is going to take the collectivity of them into consideration as an actual "block of needs" rather than as an "unity". Migration can't be solved "once", it has to be solved "every time".
* I get a strong impression that the thing that ties Pokémon to humans, more than anything else suggested in canon, is that Pokémon go with humans because they believe that assisting a human gets them to become stronger. From this follows from a long-term political point of view, that most Pokémon would grativate more towards the leaders and general main actors of nations that are currently struggling against a massive difficulty that a Pokémon can face (say: a war, climate change, or a plague) than towards the leaders of a nation that have just solved their problem and are now riding the wave of stability or fighting remnant, abstract problems (like inequity, poverty or corruption). Pokémon want a human who they feel can lead them into a fight.
* It follows from the above that Pokémon are going to prefer political agents (leaders, rioters, secrtaries, whatever) who incorporate them into the method of their solutions. Most Pokémon won't care much to ride the situation with a law enforcer if the solution of the law enforcer when facing a problem is not to send out their Pokémon but instead pull out a taser, let alone a machine gun (hello, USA).
I hope any of these help!
