How does polybius say mob rules come about?

Polybius suggests that mob rule arises from the degeneration of political systems, particularly when democracy devolves into an unchecked form of popular rule. He argues that as citizens become increasingly disconnected from responsible governance, they may be swayed by demagogues and emotional appeals, leading to a loss of rational decision-making. This shift can result in chaos and the eventual rise of tyranny, as the desires of the mob overshadow the principles of justice and order. Thus, mob rule emerges from the imbalance and corruption of democratic ideals.