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.
This kind of response is why we can't talk about all sorts of hot button topics on HN: people get personal. I'm sometimes guilty of it myself.
given that we do now live in a society with a universal right to vote the need for an educated populace esp. regarding matters of civil society is more important than ever.
You've also misinterpreted the parent comment as they wrote nothing about contemporary intelligence. They're instead referring to structural forces that negatively impact critical thinking. See: the glut of commentary from otherwise highly intelligent and accomplished people reporting their own ability to focus being negatively impacted by social media and short-form content.
Furthermore, this is why the old school shared media outlets (the whole "back when everybody watched Walter Cronkite every night" thing) was so valuable. Few of us have the time to consider the issues with any degree of nuance or accuracy. So it's a real problem when the collective "source of truth" is poisoned by a horde of uncertified, often anonymous, charlatans spewing outright lies and incendiary half-truths, distributed at scale via algorithms designed to divide and inflame.
disclaimer: i'm fiercely anti-democracy, esp. with universal suffrage, for the exact reasons you cited.