A morally grey area, especially those in the realm of politics has always been one of BioWare's weak points (IMO). All too often the "politicians are weak or corrupt and only stand in the way of the hero with the gun" troupe shows up, and while real life politics does have those elements to it, the situation is nowhere as cut and dry, as black and white as BioWare likes to paint things. Now while I don't expect to see a political drama in the next game, it would be nice to see some murky grey areas our hero has to trudge through.
Though if the game is better served to not delve into such elements I would be okay with that as well.
P.S. The Krogan aren't blameless in their political machinations, even in ME 3. Sure, the Asari may have taken first prize in political idiot of the galaxy, but the Krogan were perfectly fine with holding the galaxy hostage to force the Genophage cure, and if their efforts are sabotaged, they would rather go to war against the very people fighting to save everyone in the galaxy than try and fight the Reapers. And all of this after Wrex's numerous conformations of total support in ME 2.
I'm not intimating they're blameless saints blinded by technology and shinies, I'm saying the era of smiling and lying and using committees and basically letting the council take all the blame/praise whilst doing the heavy logistical lifting behind the scenes with backroom deals isn't going to accomplish much, even if the Ark is large enough to be a mini-citadel of its own accord.
We see with the krogan rebellions and ME2 and 3 that the asari method was cartoonishly inept in the face of any form of organized discord or contention, particularly without other folks to nod and smile and agree and then send actual troops in, the policy of letting things exist over there out of sight and raking in benefits from illicit stuff while decrying it publicly only works when the people decrying it or some other third party lack the guns and means to make their beliefs a physical reality.
Indian Wars and the building of the Transcontinental Railroad
You're conflating social interaction at all with politics. Manifest Destiny was re-introduction and reassertion of groupthink politics, local politics was predominantly one and one or with and had very little to do with anything other than very clean and clear greed (brush wars, cattle vs sheep, settler encroachment) or personal/social contention (indian wars, chinese mistreatment and subjugation, mexican contention) which doesn't require politics to be a precedent or antecedent in the least. Most of the drive west was for the average citizen to get away from politics, period, and that's a matter of historical record, not speculation.
Not quite sure how to break this to you but life isn't like a Kotaku article, and people that think it is at that every organized group of ________ is subject to the laws of Diogenes and Machiavelli tend to be college and high school students who've spent about 5 minutes interacting with the larger world without the safety net of parental logistics and academic insulation, the real world tends to operate far more on avoiding harm and enhancing zeitgeist than any need to make _______ happen, and steadily dwindling voter turnout in the face of technological and social progression bears that out pretty absolutely.