Trumponomics 2.0 - is it all a troll?

If his policies go through, specifically tariffs and mass deportations, the economy will tank catastrophically. 

There's little disagreement about this, at least as explained by people known for honesty and thinking, anyway.

Now, some Trumpers and their adjacents will say:

Oh, he's not going to actually impose those extreme policies. These are simply negotiating tactics, from The Art of the Deal man and fabulously successful businessman.

i.e. His brilliant negotiating skill is to propose something which everyone knows he will never do in order to elicit some great compromise to his advantage.

I'll just leave that there.

Also, everyone please recall that as he attacks Mexico and Canada for their unfair trade practices, that one of the proudest achievements of his first term was to renegotiate NAFTA and replace it with a new agreement, the USMCA.

i.e. our trade agreement with Mexico and Canada.

I'll just leave that there too.

I just thought of something.

Exactly what economic problem are his tariffs supposed to solve?