Hence, separation of powers and representative democracy.
Now, if the elites only really want to dominate their subjects and collect all of the power for themselves and their own kin (which has been the case in an historic sense), then it stands to reason that society is always moving toward aristocracy. Now, if the elites are inclined to create forms of aristocracy, then it makes sense that they'd want to subdue the votes of the common people.
Now, if the top pillars of society are privileged, wealthy, and politically powerful, how can they retain their power, wealth, and privilege for generations to come (much like a royal family used to a few centuries back)? Basically, if the uneducated poor, unprivileged people were not able to pass a test, their interests would most likely be lost and the elites would keep nominating candidates who do not serve the interests of the uneducated and poor.