Detroit is in shambles, because it produced a terrible work product and let Unions force GM and others to pay a low skilled assembly line worker, as much as a medical doctor. Imposing huge tariffs on imported goods, may let a few auto workers go back to the days of getting huge paychecks for repetitive manual labor, but the rest of us would see the prices of everything from cars, to cell phones go through the roof. And that is before other countries retaliate with their own tariffs. These people that believe Trump can simply enact extreme protectionist policies without effecting prices or our ability to export goods are amazing. Standing up to countries that block American imports is one thing. Using the police power of the state to punish free Americans who open up a factory in another country is another. A vote for Trump is a vote for two things. 1. Hillary and 2. Insanity.
You need to update you preconceptions. Unions only represent 10% of manufacturing workers now.
An American who opens a factory in another country is a traitor and I'd go a lot further than Trump in punishing that brand of treason.
When Great Britain was a world industrial power they hanged businessmen who sold industrial techniques and machinery to foreigners.