Would like to see more investment in manufacturing here in the United States. Apple has to recognize that unstable relations between the United States, the EU, and China (along with South Korea and others)could leave them in a precarious position with their physical manufacturing capabilities. If China says, give us U.S. user data, or give us the capability to build your new 3D camera or we shut your facilities down, what will Apple do? Not to mention South Korea's antics with raiding Apple's South Korean offices and whatnot. The same goes for other US firms - EU you better watch out too.
It would need a lot of investment. You need glass makers, metal shops, semiconductor shops all close together to emulate what is there in China right now. I don't know if its really possible in the US.
You'd need a sort of 'motor city' for electronics. Something like what Detroit was for cars, or like what Shenzhen is now.
I'm surprised that no stateside port cities have tried to encourage that sort of thing; there are plenty of negative externalities, but I would still LEAP to move to such an initiative.
It's like...I want to create something that could make a difference for people, but all that I see in our current tech cities is faux do-goodiness, iniquity, and seething resentment. It's a bunch of people saying that they want to save the world while reaching into the pockets of people who can't afford it, and it hurts to be unfailingly lumped into that sort of behavior.
It's possible. It's expensive to build out and would take a decade to do comprehensively. Apple can easily afford to do it (How badly do their shareholders want that? Not that badly I suspect).
Most of the things in question have already previously been manufactured in the US at one point or another. The specialization / knowledge is already here. The base manufacturing capability, the buildings/plants, the inexpensive energy, the automation capabilities, the software, the access to cheap commodities, is already here.
The US is the world's second largest manufacturer, by a very wide margin to the others down the list. Only China compares in scale globally.
Call up Texas and Corning, make a deal backed with billions in investment, build the plants, and you'll be making as much glass in the US as you want within three or four years.