"TSMC and Samsumg have fabs in the USoA"
How long before the tangerine terror fucks that up?
Your question is valid. The answer is simple. the "Tangerine Terror" can only stop new fabs getting here. The fabs that TSMC and Samsung already have in USoAn soil will remain there AND be upgraded.
The sole process of building a fab that can sustain the cleanliness needed for chipmaking (significantly more clean particle wise than an Operating Room, although less asceptic) is super-Expensive. even before you deploy the Litho Equipment. Also, the load bearing on the ceiling for the waffer transport pods is out of this world. Also, moving around the litho equipment after deployment is super expensive too (revalidation and re-calibration galore)
Also, with the world the way it is, neither Samsung nor TSMC can afford to risk full stop production in the mother-land due to military action (NorK or China), or to Earthquakes (Pacific Fire Ring). So they will keep building outside of their motherland. Be that the USoA, Canada or europe, Who knows?
So, is not like Samsumg or TSMC will vacate the USoAn fabs and let the buildings go delerict, or sell the empty husks of the buildings to "someone else" for pennies on the dollar.
If they get feed up with the "Orange Terror", they will stop new GreenField fab building, expansion projects, and maybe even cancel projects in very early stages of construction, but very advanced constrution or operational fabs will go ahead.