I am surprised by the AI capability to expand in my current Horatio game (Normal difficulty).

Before turn 35 I got a message that the Sophons were about to win the game (Conquest victory).  By the time I got to their constellation, I took this screenshot on turn 70 (still haven't yet discovered all of their systems):

How are Sophons able to expand so fast on Normal difficulty? I am pretty sure it would be impossible for a human to accomplish this, correct? Or do Sophons have an ability that helps curb happiness issues? Forget the fact they have no pirates or nearby factions, those are possibly an issue too, but even under ideal circumstances such as this, I don't know how they could have been able to expand so fast and maintain it. Is there a way to debug a save to see what their planets look like?

Also, I think the "so and so is about to win the game by conquest" message needs tweaking. I don't think the Sophons were anywhere close to winning the game, so I'm curious why it came up so early.  They are definitely in the lead, but I assume maybe they were at the halfway point, at best (and probably not even).  My current game requires 22 systems to win it. Maybe I should turn conquest off with the AI expansion working like this, especially if it has expansion bonuses the player doesn't get.

Good to at least know they are getting the -N approval penalties.

I'm currently playing a Horatio game where the Riftborn have 14 colonies already.  I have 9/7 and having to really focus happiness buildings in a few systems to prevent Unhappiness and Revolt.  This is with a +2 Approval & +2 Hot Approval bonus on my Horatio so far, and Toys 4 Boys running. I have no idea how the Riftborn are able to do this, except to say that low Approval must not be so bad when you are in something other than Dictatorship. There is no way I could jump from 9 to 14 systems and be able to keep all those systems from Revolt. 

One thing that did hurt me was switching political parties.  I though that I would be able to use Propaganda to allow a new polital party to slowly rise, but after 10 turns in a row, in 1 system I noticed that it did not impact the next election at all, so I think that could be a bug. Not only did I not have new religious senators with the new pop, but there was 0 added religious sentiment to the system based on the propaganda (I only got a tiny amount of religious pressure because I researched 1 religious tech).

After switching back to Ecologists, I should be able to take a few more systems, but I doubt I'll be able to take 5 more to catch up. If this is "by design" for Dactorships, then that's not such a bad thing to know it's at least working as intended.

Riftborn are known as being a wide faction because each outpost they create is independent, hence doesn't draw upon from established colonies like it does for everyone else with respect to Food(except Vaulters since they don't have outposts with their super colonizer). If Riftborn get Thinkers and Tinkers I(Pulsos Minor Faction trait), they can colonize outposts in as little as 1 turn after they explore enough curiosities. Their population doesn't take Food and Industry production is unaffected by System Happiness, making them the ideal Wide Empire(although their Dust, Science and Influence output does take a hit if they go haywire on expansion). Fortunately for Riftborn, they have Biophobic trait. This allows them to forego Loyalty improvements since planet malus is largely ignored due to their Sterile bias. Riftborn also have +5 to Industry, Dust and Science on their population, making them one of the strongest population in Endless Space 2(outside of Cravers on unspoiled planets... Extreme Foremen on custom Gene Hunter is best custom faction to date for me. Unfallen are strong on Fertile worlds but only Fertile worlds, else your Horatio beat them with +3 Food). Furthermore, you can prevent rebellion by supressing it with force or by "bribing" the populace with luxuries. Only Government type where you don't have to do this is Autocracy(Dictatorship, rebellion occurs at Unhappy(29% Loyalty and below)). Also if you play on Harder Difficulties, the AI gets a flat Loyalty Bonus in addition to a FIDS bonus on their planets. This allows them to go crazy on colonization without having to worry about overcolonization(which gives them a huge early game advantage on Food, Dust, Science and Influence production).

My suggestion for you as Horatio is to focus on Gene-Splicing the following factions: Z'Vali(+1 Science, +2 Loyalty), Sisters of Mercy(+10 Ground Damage, +2 Loyalty), Kalgeros(+3 Loyalty) and Kal'Tik'Ma(+3 Loyalty). Doing all of them yields +10 Loyalty or enough to ignore every planet malus in the game. If you're lucky enough to Gene Splice base Horatio, eh you get +2 Food/+1 Loyalty as well. All other Major/Minor Factions yield FIDS yields, with base United Empire(not Sheredyn or Mezari), Baghba and Illo yielding +1 Influence respectively. Since you're in a Dictatorship as Horatio, I believe the Independent Laws are different than they are under Federation, Republic and Democracy where Senator Bob Act would yield +2 Loyalty(+3 in Republic) per person at the cost of -2 Dust per person. Thing is, if you Gene Splice those factions, you won't have need for Senator Bob Act, much less any Loyalty/Happiness system improvements.

If you have random events toggled, you get Kalgeros at some point in every game so that's a guaranteed +3 right there once assimilated. Just hope you come across one or two more of them to eliminate the bulk of planet malus on a system.

PS: Another tactic to take, and one I employed as Riftborn, is to utilize Benthic Gems. If you hold off on System Development and unlock Tier 3 Luxuries and are lucky enough for Benthic Gems to spawn in your sphere of the Universe, you can effectively eliminate overcolonization altogether by using Benthic Gems twice. Granted this only works on systems you colonize and quickly upgrade to level 4(won't work on colonies you conquer unless they're level 2 or below since you need two system upgrades to get the full Benthic Gem effect) but once you obtain Benthic Gems and upgrade your systems, you can colonize the Universe and never have to worry about overcolonization ever again(Conquest Victory = given at that point).