Tribes require obedience to a hierarchy of power or a power structure where social organisation and all its institution's and corporation's primary function is to signal obedience to the tribal hierarchy as a first duty - see my posts on obedience.
There are always only ever two tribes fighting for the top spoils.
The winner in that time and place is what we euphemistically call the government or the state. the way in which the winning tribe wins, is by what is also euphemistically called 'a democratic election', to make it sound normal and fair.
But in the end a democratic election is not a way to share fairness at all. It is to signal obedience to the winning hierarchy. If your tribe wins, then bingo! If not you and your friends and family are in trouble.
This is why the vote should only really be given to people who can show clearly they know what they are voting for. The alternative is to wreak havoc.
Underneath the current top two trines are a myriad of lower competing tribes, all trying to get a piece of the current leading tribe. Have you noticed how people, across the political spectrum, only pay respect to wealth and power. As a primary function within our tribe.
There may be times when there are more or less than two leading tribes. But this is an efficient configuration. Only one tribe means there is no competition for the spoils - a monopoly which means things will get more costly and be worse quality, economically and politically. More than 2 tribes means there are too many and this is also an excess cost. Only two exactly are required to maximise efficiency and block out monopoly.
The most efficient way is just two tribe. Any more or any less is not naturally efficient. This is why there are always only two effective tribes with enough power, to gain power.
Those in the minor tribes who signal obedience in the best way tend to be invited to join one of the leading tribes. These people will noticeably change their character immediately if they make the move. No one will understand why they suddenly changed. WIthin all tribes it's forbidden to say that all of us are obedient instruments of the tribal masters we willingly select. It is regarded as heresy and you will be sent into exile if you oppose the tribal narrative.
Each tribe has a Master - that is, a narrative. A story which all members of a tribe follow religiously. If they do not follow it they will be sent into exile. If they do follow it this is the biggest way to climb social within the tribe.