According to Arendt, an increase in the population leads to a blurring of the distinction between the political and the private, an important feature of the modern age.
The political realm is the realm of rights, freedom, and equality: all the aspects of liberal democracy that we in democratic states take for granted. The private realm, on the other hand, is a realm of necessity, where man's biological needs are met. Here, there is no place for freedom, as man cannot escape from the dictates of his most basic requirements.
On Arendt's reading, an increase in population leads to a growing organization of private matters by public bodies. Inevitably, this has the effect of increasing the power and reach of the state, handing over control of what was previously the unique preserve of individuals to a powerful bureaucracy. In such a system, politics is no longer a rule of equals, but a rule of rules—rule by bureaucracy, by no one.