Ordinary people have few illusions about their abilities. They know their limits and have a tendency to say, "let me think about this" and walk away to do their own research.
The Smart people do not. Secure in the belief in their own superiority they do not check things out but eagerly will swallow what ever you feed them as long as you can make it sound logical and intelligent.
You just have to twist the facts a bit, leave a few things out, flatter and presto! They are eating out of your hand. Ready to hand over their wallet, child and even their life if you have enough time.
AND make THEM appear logical and intelligent. The essence of successful brainwashing...