Every time I play I end up being flooded by Militarists. It's not particularly fun and a noticable amount of quests require other parties to be popular. What can help with this?

You can see what events increase each party in the senate screen. Just drag your mouse on the party you want to learn about.

Militarist tend to be majority. They appears due a lot of casual situations, like building a fleet (even defensive) or fighting against pirates. If you go at war, you can be almost sure that militarits will rule your senate next elections. Even the sight of ennemies near of your empire might empower the militarist party.

But you can overcome its natural strenght by many ways. To set-up a peacefull climate around your empire is the first big step, be in peace with as much empire than you can, make trade with them, etc. Also, you can try to solve as much conflict as you can via diplomatic demands, and use the pacifist or non-military reactions. You can hire non-militarist heroes, boost and favor the non-militarists pops, manipulate your elections against militarists. There might be others stuff to do.

Some governements can combine fully several politics, and so be able to use all the laws of those politics. Democracy, for instance is the best for that. Even if militarists annoy you, you can have access to all the laws of another party if you favor it enough.

Some situations will push you governement to militarist anyway. For instance, a neigbour craver threatening you and attacjing you will make your militarist party super strong ,because of the constant tense that such a foe can produce. But honnestly, it's also the best thing that can happen to you. Against such ennemy, you need a powerful militarist goverment. The annoying part is after the war, if you won it. It's very hard to knock down an installed militarist party. You can do it by manipulate elections after elections, and spend a lot of energy to favor other parties. It's hard but doable.

This is actually a good question. What are some of the active things a player can do to promote ecology, religious, industrial, ect... I know combat inside and out but i would to know if there is a list of available actions for what party.

Sorry I cant assist herr 

I know when in the Senate Window or the Population window you can mouse over the icon/name for the different political parties and it will list which actions will boost that party.

However, it is not as detailed as it could be, for example not saying which things might have less or more impact, or whether all the actions are weighted equally, etc.  From my 3 games so far, I wonder if there is a natural way to put the Religious party in power?  Their tooltip list seems the shortest out of all the parties, with only a handful of actions affecting it, and as far as I could tell, the only really controllable one was building Influence buildings, and there are comparatively few of those...

I also am suffering from "Militarists always get there" syndrome. The pull that Militarists get from the actions that are absolutely necessary (fighting off pirates, building ships) is way too strong. I don't think that Militarists should get ANY influence from fighting off pirate fleets and even systems... If and only if you are going to war with another faction you should get Militarists in, because, well, Jingle Bells law isn't that great when you're not warring an actual faction.

I am still experimenting with the game; but I don't see a natural and fun way to put Environmentalists or Religious party in power, and when Industrialists have their asses handed to them by Militarists it's a looooooong way for them to get back into the top spot.

I have also been running into this issue, and it seems to have been around for a while.  If it was already an issue for some people earlier, the ramped-up Pirate presence certainly gives much more reason for your population to turn Miltarist now than before as well.  Especially when you consider, that with the way pirates work earliy-game, and how you can't control whether your systems/fleets get attacked by other factions or not, it seems those 2 factors should not count towards Miltarist politics much, if at all, if they are comepletely necessary/unavoidable.

Is this something we should bring to the attention of the devs?