First of all the Patriots were not even a simple majority. Turns out you don't need a majority to win what is basically a war of insurgency. There are several modern analogs that reflect this reality.
Second of all the country was founded by elites. It wasn't that farmers could do critical thinking (whatever that really means) it was that the punitive British response aligned economic incentives across class, and across North and South. So a large enough slice of the populace was ready to be sufficiently bought in on the propaganda of a few outstanding men.
Thirdly, your conception of history is wrong. Small elites always rule societies. America was not a democracy at its founding, that is if you take democracy to be the 21st century standard of universal suffrage. Societies are less about some arbitrary standard of critical thinking and more a contingent set of circumstances and incentives.
It's a bit ironic in your rather tired critique of modern culture you reveal another truth - those who complain about the contemporary intelligence of the masses often leave much to be desired in their own supposed superiority.
You should read more.