IMHO, the reason is not really to protect US manufacturers. It is about long-running negative balance of trade between US and the rest of the world. Protection

IMHO, the reason is not really to protect US manufacturers. It is about long-running negative balance of trade between US and the rest of the world. Protectionism rhetoric is a sugar-coat for Americans who will have to foot the bill by paying more for imported goods, but honestly, who else should? https://en.wikipedia.org/wiki/United_States_Balance_of_trade https://en.wikipedia.org/wiki/United_States_Balance_of_trade