Near the end of the Republic Socrates decides to drive this point home by showing Adeimantus what happens to a regime when its parents and educators neglect the proper moral education of its children. In the course of this chilling illustration Adeimantus comes to discover a dark and ominous secret: without proper moral conditioning a regime's "defining principle" will be the source of its ultimate destruction. For democracy, that defining principle is freedom. According to Socrates, freedom makes a democracy but freedom also eventually breaks a democracy.
For Socrates, democracy's "insatiable desire for freedom and neglect of other things" end up putting it "in need of a dictatorship." The short version of his theory is that the combination of freedom and poor education in a democracy render the citizens incapable of mastering their impulses and deferring gratification. The reckless pursuit of freedom leads the citizens to raze moral barriers, deny traditional authority, and abandon established methods of education. Eventually, this uninhibited quest for personal freedom forces the public to welcome the tyrant. Says Socrates: "Extreme freedom can't be expected to lead to anything but a change to extreme slavery, whether for a private individual or for a city."
The article goes on to reveal how Socrates pretty much predicted the election of Barack Obama.