I support, although I am worried if it will add too much complexity to the game.
Maybe there could be a militaristic government where cities had increased production, but grew at a slower rate (as if the government were drafting more people for the military than normal, so the population slowed as a result)
Maybe there could be some sort of genocidal government where cities taken took much higher collateral, and i'm not sure if I should add in a nerf, as taking destroyed cities may be a curse in itself.
Maybe even a government based on trade, where you would gain 5% of each of your allies' profit, and 2% of the profit of anybody you are at peace with. The drawback could be that ending a peace treaty would cause a slowing of your economy in every city, and ending an alliance would cause a larger decrease, where ending the subsequent peace treaty would cause an even further decrease. Having allies die would cause a similar effect, so it would require players to be more conscious of who they ally, while providing a benefit from those who you do ally.
One last one I can think of is a communist government. Every time you completely take a country, the values of every country you have is averaged, and the resulting country has the same income as all of your other countries. For example, you start off with one country that has 100 income, and you take a country that has 50 income. The value of both of your countries would be averaged (75) and distributed to both countries. This would permanently adjust the income, so if somebody took the country that WAS 100 income, they would be taking a country worth 75 income (at least, at 100% income). Since your countries are already all the same, losing a country will not effect the income of each of your countries. Since your countries are all the same, it makes it simple, yet ineffective to attack in areas. There is no weak point of the nation, as attacking anywhere will lead to the same effect. This is both a blessing and a curse, as there is nowhere that is critical to keep defended, yet, everywhere must be defended equally. This would be more useful in attacking rich nations, for if you took the USA: Atlantic with an average of 200 income per country, that land would lower to slightly higher than 200 income, and if taken back by the defender, would be land that is worth much less. However, if you take South Sudan, and had an average income of 200, and then South Sudan were taken back, your foe would be given land that is worth much more, and your enemy could build upon this.