Aristotle made a distinction between democracy and polity that has been obscured over time. Both are technically 'rule by citizens', but a 'polity' implied rule by virtuous citizens — citizens who are informed, reasonable, and dedicated to the community above their own individual interests — while a 'democracy' implied rule by the ignorant and intemperate masses. Aristotle thought the first was the best form of government, if achievable, while the second was the worst, needless to say. But during the Enlightenment (16th-17th century) philosophical thinkers came to the conclusion that all men had the capacity for reason, given the opportunity, and so the two terms blended together: democracy came to mean a polity-of-all, not a decadent of rule by the ignorant.
Of course, the key phrase there is 'given the opportunity'. Aristotle's era was constrained by the fact that it was primarily an agricultural society, in which the majority of the population was illiterate, and too preoccupied with essential labor to gain the acumen needed for 'virtuous' decision making. Enlightenment thinkers held that booming literacy rates and the distribution of printed media would correct that essential imbalance, creating a much broader base of reasoned thought. This idea was picked up in the 19th and early 20th centuries in pushes for publication education — e.g., John Dewey's "Democracy and Education", which held out the idea of using education to create proper democratic citizens — and that theme is still prevalent, at least in Liberal Arts curricula. Education has broadly been seen as a means for giving citizens the opportunity to become virtuous citizens in Aristotle's sense.
However, the last 40 years or so have shown that this solution is not without flaws. First, the term 'education' covers a wide range of activities, not all of which are suited to the production of better citizens. Primary and secondary public education (as a number of social scientists pointed out in the last century) has de-evolved to training children into basic skills they need for work as an industrial labor force: how to take instruction and memorize simple facts without complaint; mastering the basic intellectual and communication skills needed to work within an organization. likewise, higher education has increasingly pigeon-holed students into technical proficiencies and professional structures, creating graduates who are extremely skilled within their field, but whose skills do not translate to any subject outside that narrow frame of reference. If we think about Hannah Arendt's tripartite distinction between labor, work, and action, Aristotle's democracy was plagued by those who were trapped in labor (the ceaseless expenditure of effort to produce the ongoing necessities of mere life), but modern Liberal democracy is plagued by those who are trapped in work (the ceaseless expenditure of effort to produce concrete goods for social exchange and consumption). Both modes prevent people from rising to the level of action, where all political interaction takes place. The mode of action demands expendable free time that can be applied to thought and discussion, and the development of reasoning skills that transcend the technical skills of mere production.
Second, the modern era has brought on a flood of information, without generally increasing the capacity of individual citizens to filter and process that information. People confronted with such a wall of noise will often retreat from it, either throwing up their hands and abandoning the political world, or clinging to pre-given beliefs and prejudices with stubborn resistance. Much of the modern partisan divide in the US can be traced back to those who have closed the door on all information they disagree with, merely to defend against the raging discordant onslaught of contrary opinion.
The push for 'Liberal Arts' education that began back in the '60s and '70s tried to work on these flaws in the Liberal Democracy model, both by increasing students' exposure to topics outside their immediate technical needs and by developing reasoning skills capable of parsing a greater influx of contradictory information. However, Liberal Arts curricula have historically been opposed by many political actors, who worry that a thoughtful, reasoning electorate will diminish their control over political outcomes. It's a difficult and ongoing problem, where proper education stands as both a boon and a threat to established political power structures.