There are also other red flags, that are accessible to anybody, not only the educated ones your article is aimed at. If you look at the facial expressions of politicians you should be able to see deception in most of them.
Yet parents train their infants to believe the lies they tell them, like the Santa bullshit. Worse they offer gifts to reward their stupidity.
The problem is that emotions lead people over reason. Emotions bend rationality. So, when someone is emotionally trapped then they can't think about your red flags.
And in our societies, politicians and leaders are there because they are like trained athletes in deception, and they have emotionally stupid people in front of them. Thanks to Santa...