Distilled, Aristotle thought rhetoric good for democracy, though his definition of “by the people” was closer to our Founding Fathers’ intent of only certain people than to today’s more-the-merrier model. Given this assumption of a narrow, educated, self-governing populace, Aristotle likely envisioned that those practicing rhetoric would be guided by accepted rules of argument and engagement, emphasizing ethos (trust and credibility), pathos (appropriate use of emotion) and logos (logical argument and facts).
Plato, who was Aristotle’s mentor, thought otherwise — that rhetoric, or the art of persuasion, in the wrong hands was dangerous and likely to be abused to appeal to people’s base motives. He foresaw the unethical, dishonest uses that a skilled but immoral speaker could put his persuasive powers to, with credulous people eager to believe or buy whatever he was selling.
Which brings us unavoidably to Donald Trump, as if you hadn’t guessed.