Re: There's no practical way to implement what Trump wants
Only things that physically cross through customs into the USA actually get duty. Trump has been quite vociferous in trying to stop other countries taxing pure IP crossing borders e.g. movies, software services etc.
A chip's price includes:
1) Printing the wafer
2) wafer testing
3) packaging and package testing
4) NRE for mask sets, setups etc
5) semiconductor or fab/process SDK IP (e.g. ram cell designs)
6) Core module IP (e.g. licences from 3rd parties for cpu cores, usb modules)
7) Functional design IP (the functional chip design)
8) profit margin
Only #1 has to cross the US border from TSMC. All the others are either things that could be done in the US without building fabs, or are pure IP charges that don't attract duty.
When I was making chips
1) Israel
2) USA (wafers tested by the chip designers)
3) Thailand (chips diced and packaged)
4) Israel - stays in Israel
5) Included in NRE but could be broken out
6) Poland
7) USA chip designer
A consequence of high tariffs is that all countries which have them, also have "duty-free export zones" where factories that make products for export from imported materials are located. If the USA persists with high tariffs it will also establish these e.g. in Detroit, San Diego.
It is easy to see Apple or TSMC putting a packaging plant in the USA, and importing wafers. Wafers would be the only part tariffed. The cost of wafers in an Apple product is probably negligible.