Another Medium political writer that has no idea of how political messaging works.
Here's some math: If Mr. Trump has 40% approval rating and there are 235m voters, he should get 94m votes. He didn't in 2016. He won't on November 3.
Here's why. Much of that 40% aprroval is soft support. This demographic can find all sorts of reasons not to make the trip to the polls. Political parties are always trying to convince the soft support of other side to stay home on election day. Negative advertising is designed just for this purpose.
I doubt it very much that Mr. Trump read a psychology book and learned how to put despair in people. Rather his actions speak more towards a narcissist about to lose his power base.
The debate served a purpose in causing a few hundred thousand soft Trump supporters not to vote. Which is a big deal in a close election. But give all the credit to Mr. Trump for shooting himself in the foot.