"There is an evil I have seen under the sun, the sort of error that arises from a ruler: Fools are put in many high positions, while the rich occupy the low ones. I have seen slaves on horseback while princes go on foot like slaves." NIV translation
The problem with the rulers of this world, is that they put fools in places of authority. These fools have big ideas of their own instead of the wisdom that is from God. The rich that he speaks of is those who have the things of God in their hearts and minds. Have you noticed how those that are serving the Lord (princes) have to walk along as the poor in this world? Just look at any ministry that is following the Word of God and you will see that they do not live the high life.
"Whoever digs a pit may fall into it; whoever breaks through a wall may be bitten by a snake. Whoever quarries stones may be injured by them; whoever splits logs may be endangered by them. If the ax is dull and its edge unsharpened, more strength is needed but skill will bring success. If a snake bites before it is charmed, there is no profit for the charmer." NIV translation
Now, Solomon compares the dangers of having fools in charge with some of the risks found in a person's normal work. He does this to illustrate the dangers of believing that politics have the answer to the problems of everyday life.
"Words from a wise man's mouth are gracious, but a fool is consumed by his own lips. At the beginning his words are folly; at the end they are wicked madness - and the fool multiplies words. No one knows what is coming - who can tell him what will happen after him? A fool's work wearies him, he does not know the way to town." NIV translation
The pattern of fools in high places is that they may start with some ideas that seem a little odd but at the end they can be downright evil. An example of what Solomon is speaking of is the rise and fall of Adolph Hitler. He started out being looked at like a foolish child by the rest of the world until he progressed into "wicked madness" and would not accept counsel from anyone.
"Woe to you, O land whose king was a servant and whose princes feast in the morning. Blessed are you, O land whose king is of noble birth and whose princes eat at a proper time - for strength and not for drunkenness." NIV translation
When fools are in high places, it is like having a child in charge and they do nothing but serve their own desires. Solomon contrasts the fate of these nations with those who have godly rulers that look after the people.