It's amazing how many people believe this fraud
Though I get your general sentiment, Trump represents one side of human life that, sadly, will probably never leave even sophisticated societies. The question is more how do you mitigate how many people use this mode of thinking to the detriment 0f other more useful modes in a sophisticated civilization..
I say mitigate and detriment to other modes because I don't think that this way of thinking is all bad. I feel this mode of thinking has its uses. One thing that comes to mind is that it is especially useful in emergencies when one cannot afford to take time to think something through. Indeed what we consider our more 'animal' tendencies (very unfair to animals who can be just as rational as we) are necessary for survival.
The problem comes when this emotional thinking becomes a primary mode where things aren't always an emergency. An extremely complex society demands we think things through and have relevant
facts needed to support an effective decision making analysis.
One way to mitigate this phenomenon would be for our politicians to fly straight, to care about their constituencies (ALL of them, yes I'm talking to the racist politicians in our gov't). To stop lying to them about change. There are other countries whose governments actually enjoy a majority favourable view from its people). Again, this is mitigation, not eradication.
Undoubtedly, statistically I would think, many of Trumps supporters are like him, or at least his public face. Spiteful, incorrigible, mean and hateful. However, many are not. They are good people, just mad and have allowed themselves to be "seduced" by him due to their feelings of hopelessness and despair over gov't ineptitude.
There may also be this issue of "facts". Where do we get our facts from? This is a sticky question and not easily fielded. Not many of us do our own, extensive research. If you think you have a fact (that is false) and make decisions of it, depending on the fact and what you do, you could appear extremely irrational to others, but really, in the context of believing that 'fact' you are being rational.
Its almost embarrassing to have to defend against Trump. To many of us it seems like a no-brainer, literally. But we all don't work off the same 'facts'* and in the correct context. And not everyone is rational. And that irrational side is not 'abnormal' as such (at least its underpinnings). Like it or not, we have to deal, rationality doesn't come automata with the human package and neither do 'facts'.
*The activity of gathering and substantiating findings into facts, including degrees of certainty about those 'facts' is acquired just from living. However, that would be an informal
science applied to the informalities of living. Here, you can be totally wrong about something, but it works. This is as opposed to the difficulty of a formalized
science of critical analysis which is not acquired just from living and requires more rigorous learning as a discipline. Making effective social decisions in a complex society requires the latter come first.