In contrast to Menenius' claim early in the play that the state is an organic whole, there is little social cohesion between the classes of Rome, and this makes for political friction. The Tribunes only recognise the rights of the people and undermine the election of Coriolanus to the consulship. Coriolanus on the other hand is certain that mixed government cannot function effectively, that there must be a natural ruler at the head of the state; he stands for the nobility, the class who built Rome and the warriors who defend its position against exterior threats. These attitudes make for intense 'class' prejudices emanating both up and down the social hierarchy.
The issue of Coriolanus' election escalates the clash between the nobles and the Tribunes. With the expulsion of Coriolanus in Act III, power falls to the Tribunes to a much greater degree than most of the nobles realise. Their weakness is affirmed by their willingness to sacrifice Coriolanus, their only realistic hope of regaining power lost to the Tribunes, rather than risk provoking civil war.
Shakespeare presents political conflict between opposing groups in Rome through the interaction of individuals. This is what the playwright was interested in - the relationship between power and individual action, not the historical processes of the 'Wheel of Fortune' or cycles of government. Central to Shakespeare's English history plays are shifts in power and tensions between legitimacy and de facto force. In Coriolanus establishment and retention of power is more complicated