You are missing the point. The point is that they pay almost no taxes now. Even if Trump, by some miracle, managed to score a net-zero tax bill for Apple, that pretty much puts them exactly where they already are.
Now all Trump would have to do is convince workers that it's in their benefit to work for the same wages, benefits and under the same conditions as the Chinese workers. And don't forget, all the components that are built and raw materials which are processed in China now need to be transferred to the USA or also manufactured here. Which again means the manufacturers of those components need to move to USA and operate at margins that their foreign counterparts do.
And even after all of this, their products at best stay the same price, at worse still become more expensive. Only now there are fewer people who can afford them since they're working for much less.
Well, there is one other way... Trump can just subsidize Apple. Pay them to stay here.