America already has a huge semiconductor industry (45% of the market by revenue), it’s not like all the fabs shipped off to Taiwan and Korea. “Regain access” isn’t a problem, but ramping up capacity would take a couple of years.
What matters is not revenue, but physical manufacturing, and where it is.
The global industry today is paralysed by lack of nothing more than few cent microcontrollers.
As I said above, restoring working of existing fabs will require rebuilding the entire Asian supply chain for chemicals, spare parts, consumables, and services.
LAM, KLA, Advanced Materials, ASML — their tools are 50%+ foreign parts, and materials.
As I said, we produce a lot of high-end semiconductors in the USA: the supply chains are already there, they are simply more expensive. If consumer semiconductor production had to move back to the states, we would have to repurpose those supply chains, they probably would never be as cheap, but we are talking 10 or 20%, not something horribly crippling to the economy.
Non-fluoropolymer high temperature super low outgassing plastics, and plastic parts used in semi equipment for example. That's an expertise that simply never existed in the West, and will have to be built from scratch, taking precious years.