Replying to multiple posts
Manufacturing in the US - if Apple reaches the point where they want to do it in an automated fashion, instead of having people put together all the fiddly bits, then it doesn't really matter much where the factory is located. Obviously bringing that sort of manufacturing back to the US wouldn't bring a whole lot of jobs either. I suspect that as automation grows, more manufacturing will come back to the US, but any jobs they create will not help those lower skilled people who were displaced when manufacturing jobs started leaving the US.
Trump - he knows what he's doing, and he's pandering to the "angry white man" contingent of the republican party that blames everyone else (liberals/Obama, illegal aliens / non-whites, China, congress, etc.) for their own problems. Trump tells them he'll make America great, bring back jobs, build a wall to keep out illegals, and so forth without regard to how he will do these things or if they are even constitutional. I have to admit I thought he'd stick his foot in his mouth and flame out long ago, but his supporters like that he speaks his mind. Say what you want about him, he doesn't have speechwriters like everyone else, and he's becoming more polished as far as how he conducts himself (though he still says outrageous things) so he looks to make a serious run. I think if he's elected he would probably be forced to govern from the center. We had an actor as president in the 80s and survived, could a real estate tycoon be any worse?
Corporation tax - while it is the too high in the US, the democrats won't lower it without removing loopholes that allow some companies to pay nothing or nearly so, and the republicans won't allow that because it would mean raising taxes on some corporations that contribute (tax deductible!) to their campaigns. In the end it doesn't matter, because the money Apple and others holds overseas is taxable, just not today.
Moving corporate HQ - while it is doable the PR hit especially for a company like Apple would be massive, so it is not something likely to happen. I agree there's no way they'd move to China. The way that US drug companies have been moving overseas is via a reverse merger. They get "acquired" by a European company and the merged entity has its HQ there. I put quotes around acquired because the acquirer is much smaller thus the name reverse merger. I think simply moving overseas may trigger taxes due on overseas cash first which is why you never see successful US multinationals move their HQ out of the US.