That is what people like trump don't understand (not surprising). Instead of gradually rebuilding the manufacturing capabilities of the US while supporting essential industries (like steel production) to create competition, they think slapping tariff will magically make the domestic manufacturing come back. Like you said, the US manufacturers will just ride along the coattails of tariffs instead of trying to be competitive and/or expand their production (they have no incentive to do so).
Again, knowing how short-sighted the US politicians and the society as a whole (e.g., look at how a majority of corps only care about short-term/quarterly profit) have become, it is not surprising but saddening to observe (because I have been living in the US for a bit over two decades and cannot move back to my home country, which is, at the moment, riddle with civil war).