In as few words as possible: The elites feared the mob.
Others have touched on aspects above, but I’ll try to fill in some connections to today.
The Roman Republic fits my needs as a starting place. Rome was a uniquely large city in the western world BCE and had unique problems. Especially with food. Most of the population of what we now call Italy were farmers (or fishers). They grew the food, transported the food, distributed the food to households, cooked the food. Any disruption of this cycle brought starvation. Farming was a prestigious occupation. Most Senators were rich from large farms. Soldiers were rewarded with farms of their own in conquered provinces. They had power and knew it.
Multiply this by every other task necessary to keep a large city functioning. Elites might have supervised but the city was run literally by hand, and those hands belonged to the people who outnumbered the elites at least 100-1. Politicians who could get organized backing from them got elected as Tribune of the Plebs and had enormous power, up to vetoing Senate resolutions.
Such power depended both on elections and freemen owning their own land and businesses. History didn’t continue that way. Rome’s demise left Europe with a 1000-piece jigsaw puzzle of little fiefs, lands owned by a hierarchy of lords who controlled the peasants and their food and movement. They owned their own goons, um, knights, also looking back to Rome, which did not have a modern-style police force, although the elites had their private forces. Organizing peasants was extremely difficult and the many revolts were brutally put down.
The mob is now associated with the French Revolution, but all these earlier examples are evidence that the vastly outnumbered elites used brutality and lack of alternatives as control measures.
Enter America. In the eyes of white Europeans America was unowned, free for the taking, providing unlimited farmland that hadn’t been cut into tinier and tinier pieces. True, the colonies were given patents by the Kings that gave the governors ownership, but these were first ignored by people willing to go into the backwoods and then swept away by the Revolution. (Soldiers were promised land if they won and some revolted because the promises weren’t kept.)
The Founders were terrified of the mob. The Constitution shows that they really wanted the elites - educated, wealthy, and washed - to control the masses. They assumed that because the colonies had mostly worked that way the country would continue to have the best and brightest run things.
Enforcing that proved impossible. Elites owned land - Washington put all his money into distant land ownership and Jefferson was constantly in deep debt - but even plantations were a tiny fraction of a million square miles. The common people kept multiplying and owning land and other properties and businesses and had means to organize through political parties, the anathema of the Founders. Every small town had elected officials and town halls and public participation and that quickly spread into state government. Federal government fell to the mob. The backlash was that the wealthy found ways to took over governments, but they did so at least quasi-legally to produce the oligarchy we still call democracy today.
European countries have many histories but some variation of the common people becoming sufficiently wealthy and organized to overthrow the nobility can be found all over.
Sorry. 600 words. Couldn’t help myself.