Companies are finding it harder now to determine how to avoid paying their share of U.S. taxes. It was only a matter of time before a company like Apple would make a mistake by missing a $13.9 billion deadline. Due to their error in missing this deadline it will bring world-wide attention to this issue of tax evasion. It has been going on for far too long. Companies are now going to start taking actions for relocating back to the U.S. very soon. However, in my opinion, it will be done in a way that they will try to appear as if they're doing it for the good of the Country. It will only be to save them more money and their brand.
Although companies may move out of Ireland if the government starts acting tough, the United States would be one of their last choices. We still have a terrible tax system that demands taxes from foreign subsidiaries of American companies. Without changing that ridiculous tax law, we'll never compete against tax shelters that actually protect your privacy.
I doubt whether companies will start falling over each other to relocate to the States. President Trump hasn't done much, yet, to reduce corporate taxes and his rather erratic behavior may make companies stay away. Besides, the cost of basic labor is too high in the States and this a business fact that cannot be disputed.
No, companies will not start locating back to the US because there are too many financial incentives for them to exist elsewhere. Jobs will always be shipped overseas no matter what the new president says or does. It is cheaper to make things in China than it is in the US.