Comment by Lendal

Yes. And even if we could wave a magical wand and materialize a whole new city (or region) with thousands of new factories and also a workforce complete with training, and housing for them, and new universities to continue the training for them and their children, and new power plants to supply the power and water needs of this new region as well as a transportation infrastructure to support all this new economic activity. New airports, new rail networks, and new shipping ports. Even if all that could happen instantaneously, the result of all these new Made-in-USA goods would still be astronomically higher prices for all Americans. The US is one of the most expensive places to live in the world, and all these factories have to pay those high prices both for their construction and for their ongoing operations. (I'm assuming here the magical wand only speeds time. It doesn't produce investment capital out of thin air.) So protective tariffs would need to continue on indefinitely so all these people could keep their very expensive jobs and all Americans would be paying the bill for it, forever.