A small tariff of say 10% would completely eliminate the comparative advantage of using slave overseas labor. The off shoring would stop, and gradually manufacturing would return. It wouldn't happen overnight, just like offshoring didn't happen overnight.
10% wouldn't even cause a blip.
What would it take to bring back a companies business that would have to off set BILLIONS in expenses?
You would have to eliminate wage controls', i.e. unions, regulations, vis a vie EPA, OSHA, tort reforms, and the myriad other demands placed on businesses today.
It isn't that simple.
BTW, that “small tariff” get’s passed on to the consumer....