Violence. In 1762 Jean-Jaques Rousseau published a book titled "The Social Contract". It was the culmination of generations of philosophical debate, but it was remarkable in the way that it succinctly stated that the benefits of living in civilized society should outweigh the loss of freedom implicit in living in that society. The chief benefit is security. Each citizen gains protection of their life, of their property and their possessions. The point is that when we agree to not steal from, hurt or murder our fellow citizens, we are likewise protected from being stolen from, and being hurt or killed by our neighbors. And when a citizen transgresses against this contract, a civilized society, will rectify the wrong and penalized the wrongdoer according to laws and procedures created beforehand and applied equally to all citizens.
The idea of the social contract was a dramatic improvement over the divine right of kings and other similar rationalizations of monarchy, theology and empire. It is the philosophical underpinning of democracy. And 250+ years later, it's still just an idea. And the reason is because for every idealist who says that the freedom and security of living in a civilized country should be equally distributed to all, there's someone gaining wealth and power by saying "Except for those people. They don't count."
Implicit in the social contract is a means of enforcement. The social contract empowers the state to enact penalties up to and including the commission of violence to compel adherence to the terms of the social contract. But the nebulous 'state' does not enforce the equally nebulous 'social contract'. The platonic ideal of the social contract is embodied in the Constitution, the Bill of Rights and all of the lesser laws and ordinances which we as citizens are duty bound to obey. The 'state' too is embodied by our fellow citizens in the military, in the police, and the other regulatory agencies to which enforcement has been delegated by our government.
So when we leave the realm of philosophy and look at how the social contract works for actual citizens, it becomes obvious that the implementation of this concept could use some reform. Race and class are the right and left of problem and the oponents of measures to reduce inequality are playing an excellent game of rope-a-dope with the American public and the press. Each time someone raises a fact like "African Americans are 28 times more likely to be killed by the police" someone will claim that it's not about race, it's about crime, as if African Americans committed 28 times more crime than other Americans. If someone suggests that helping the poor would be a sensible and charitable thing to do, then someone else will state that (African American) thugs and moochers already get too many handouts and that they all just need to get married and get a good paying job. Race and class are the chicken and egg dilemma of inequality in America