You assume the rest of the world will remain open to you as you slam the door in their faces. At best you might end up in a situation where you don't have to compete with Shenzhen in your local market, but where all other markets are closed to you and open to them. Except now you won't even have access to collaborating with Shenzhen and other significant electronics hubs. I think you underestimate how much wealth moves into the U.S. because of globalization and has since the early 20th century. Now, you can argue that you won't go completely closed, but I think you will lose out in proportion to how much you close things, specially if you do it to the point that other countries find themselves needing to retaliate with their own trade barriers and alternative trade treaties, and even more so if at the same time you are also restricting flow of talent into the U.S.