The trick is to figure a con man is a con man before he cons you.
Trump is clueless. The dumbest man I have ever seen in politics. He knows nothing about anything except manipulating people who also know nothing about anything.
Apparently that farmer didn't realise that protectionism doesn't protect farmers. Maybe be less arrogant to begin with and listen to folks who warn you that a man who conned people before and now pretends he is your friend and tells you to trust him because he knows what he is doing is probably conning you.