After years of turmoil, Earth was finally united under one main government. There are multiple divisions for each subject (I.E Military, Economy, Religion, etc). Also, there is one main leader who is officially called the President. While mostly a figurehead, the President dabbles in all divisions, and usually gets the final say in decisions.
There are also five Sub Divisions per division that can overthrow the decision of their superior if they unanimously disagree. However, due ot the fact that the president gets to pick two, and the head of the division gets to pick three, the decision is rarely if ever, unanimous.