You follow two fallacies: The fallacy, that democracies will stay forever and that people in a democracy act democratic. Democracy is no virtue of its own.
"We can keep a Republic, or we will eventually end up with an Oligarchy - a tyranny of the elite." — Benjamin Franklin
Your best quote, because it shows, where we are today.
I am fully aware, that when we talk democracy in such forums as here, we all have our own artificial picture of democracy in mind, that is not the same as democracy in its genuine sense.
I would be very interested in seeing the source of the quotations from Jefferson and Franklin. "Mob rule" and "elite" do not at all sound like the expression of their day.
For the latter yes, why call it a democracy if the majority of people people don't act democratically, the opposite would be absurd. I didn't claim the former at all.
Your other logical errors, I will not comment.