When the unit stops cooperating
Here are a few biological facts: Our bodies consist of billions of cells. The cells are in constant communication with each other. They work independently of each other but, also, cooperatively with each other. The cooperation results from signals passed between the cells. The usual result of this independent plus cooperative functioning is a healthy body.
If a group of cells decides that their way of living is the only way to live, they cease cooperating with all the other cells. Instead, they seek to impose their way of living on all the other cells. The result is an unhealthy body afflicted with a cancer. Early and painful death usually results.
When the body senses signals from the obstreperous cells, it will seek to eliminate those cells by causing them to commit suicide or to kill and reabsorb them. This process is called apoptosis. The body does all these amazing things without overt hierarchical leadership or control.
Compare this completely marvelous situation with our present political situation. Are the cells of our society, in other words each of us, working cooperatively to obtain a healthy society? Are some of the cells acting mostly from self-interest? Should we act consciously to be more cooperative?