When President Trump promised to make America great again, the employees at Mid Continent Nail in Missouri probably didn’t expect he would put them out of work. But the steel tariffs imposed in June have the company hanging by a thread. Mid Continent is the largest nail manufacturer in the U.S. and has been in Missouri for more than 25 years. It had 500 employees at its Popular Bluff plant and was the second largest employer in the small town before the Trump tariffs hit. The trouble for Mid Continent is that foreign producers making nails abroad use low-price steel...