The common argument that crime is caused by poverty is a kind of slander on the poor.
To the Arab scholars of the Caliphate Aristotle was “The Master of Those Who Know.” Well, they were right. I’ve always thought Plato should be relegated to the fiction section of the library so as not to tarnish the reputation of his much wiser student. I highly recommend you read the whole of his Politics or at least read the entirety of Book 4 – Part XI to get the whole argument of the fragment below.
Aristotle – Politics – Book 4 – Part XI
Thus it is manifest that the best political community is formed by citizens of the middle class, and that those states are likely to be well-administered in which the middle class is large, and stronger if possible than both the other classes, or at any rate than either singly; for the addition of the middle class turns the scale, and prevents either of the extremes from being dominant. Great then is the good fortune of a state in which the citizens have a moderate and sufficient property; for where some possess much, and the others nothing, there may arise an extreme democracy, or a pure oligarchy; or a tyranny may grow out of either extreme- either out of the most rampant democracy, or out of an oligarchy; but it is not so likely to arise out of the middle constitutions and those akin to them. I will explain the reason of this hereafter, when I speak of the revolutions of states. The mean condition of states is clearly best, for no other is free from faction; and where the middle class is large, there are least likely to be factions and dissensions. For a similar reason large states are less liable to faction than small ones, because in them the middle class is large; whereas in small states it is easy to divide all the citizens into two classes who are either rich or poor, and to leave nothing in the middle. And democracies are safer and more permanent than oligarchies, because they have a middle class which is more numerous and has a greater share in the government; for when there is no middle class, and the poor greatly exceed in number, troubles arise, and the state soon comes to an end. A proof of the superiority of the middle dass is that the best legislators have been of a middle condition; for example, Solon, as his own verses testify; and Lycurgus, for he was not a king; and Charondas, and almost all legislators.
Basically this is why the leftists want to destroy the middle class. They know destroying it will quickly destabilize the country and allow it to be destroyed and absorbed by a world state.