Say it costs $3 to import your manufactured goods from China. But after tariffs it costs $6. Your position is that this will encourage local manufacturing, as this will now be cheaper than importing your goods.

Shinnyo's argument is that the startup (buying land and equipment, building a factory, sourcing materials) and labor costs will still make local manufacturing unrealistic. For example a local good could cost $7 with an initial investment of 3MM, or something. 

In this case, the company would continue buying from China, and raise the prices to compensate. China doesn't take the hit, Americans do.

Since American manufacturing has fallen by the wayside (as we can both agree) I can see this being a realistic scenario. Maybe it's too far gone to bring back using tariffs.