Socrates and the City of the Rich

Socrates tells us two stories in parallel. In story, we get a sequence of individual men, worse sons born to better fathers. In another story, worse political arrangements arise from better ones. What happens when a city or a soul degenerates and becomes worse? Plato extends the analogy between soul and city When he comes to consider the degenerate cases he has. Finally, if this is how justice looks in the city and the soul, what about injustice?