Okay so if his goal (as his followers interpret it, not what he believes, because whatever is rattling around his head is like blonde celebs from the 80s and 90s, the desire to eat a McDonald's meal, racism, and some sort of deeply nested insecurities his parents put there) is economic protectionism, this will surely backfire and trash the economy like brexit on steroids. This is like sawing off your legs to make you a faster runner.

There is no way the key holders of the government and economy will let him do this. Unless this is their final plan to Shock Doctrine the USA and firesale everything not nailed down and implement actual feudalism but I somehow doubt they have the stomach to pitch the country into a 40 year recession to do it. Somebody has to know that there aren't enough raw resources to claw back from this on a time frame that isn't shit their grandkids will inherit and not themselves.

Either way this is going to wreck so much shit so I have lots of doubts