In Socrates’s conversation with Glaucon and Adeimantus, the three men reach the conclusion that justice and injustice occurs in the relationship between the state and its citizens. Socrates sums up the ideal state. His model society features citizens with jobs, housing, food, and clothes. The subjects sing, converse, and care for another. The families in this state, according to Socrates, “do not exceed their means,” as excess might lead to war or poverty.
For Socrates and the two men, it’s the absence of moderation that throws the state out of whack and produces injustice. The drive to amass goods and wealth can leave one with nothing (poverty). It can propel a state and its people to act violently towards one another or with people from a different state (war).
As for how these lessons on immoderation and injustice relate to the United States right now, think about how movements like Black Lives Matter seek to address some of the extreme imbalances in this country. It’s possible to see police brutality as a result of an unjust, inordinate society where certain institutions possess far too much authority.
One could also view the rise of Donald Trump as a result of America’s lack of moderation. If more Americans, regardless of their race, felt like they lived in a just state that supplied them with their basic needs—the needs that Socrates notes—maybe they’d be less susceptible to intemperate ideas and politicians.