People who have political power have it because first they are the type of person who desires this power, and second because they are the kind of person willing and able to do what is necessary to achieve and maintain it.

Because the act of achieving power over other people automatically puts the power-seeker in an adversarial relationship with every human being on the planet, it's an unstable condition which requires active effort to maintain.

Natural selection removes from the political sphere those individuals who are not successful at identify and countering threats to their power, so the people who remain are the ones who can do this, consciously or (more likely) unconsciously.

They don't need to collaborate or conspire in order to attack threats to their power - doing so comes naturally to them. They respond in predictable ways to certain stimuli because they all share a common set of motivations centred around their common desire to hold on to their power.