The US imports way too much and our economy has been slowly dying since the 70s. Tarriffs are only a nuisance for the upperclass, they're a boon for middle class Americans because they allow more industry to come back to the United States.
Tariffs suck for everyone except for the few that suddenly see their sector protected by them.
For starters, they will shock well greased supply chains, that will cause shortages and thus price raises. Who suffer price raising the most? Then, protected industries will have quasi-monopoly power to raise prices (this is the populism behind tariffs). But other industries will suffer because they can't import their resources and have to switch to more expensive and/or lower quality locals. As an example: suppose that car makers are happy with tariffs protecting them from japanese cars, but now they have to buy expensive US steel, and have to move their assembly lines back to US where today is hard to find experienced and cheap workers. Because everyone always claim to want industry back, but then nobody wants a blue collar job if they can get a white collar one.
