"Those who don't study history are bound to repeat it." Author unknown. We have been through this before. In the early 19th century manufacturers in the US were agitating for a protective tariff. The Industrial Revolution had started in England in the textile industry just before 1800. US textile industry started soon after with men bringing plans, in their heads, usually, from England and starting textile factories. Northern states led in developing industry. The metal working industry in England was also ahead of the rest of the world. The US Southern states had a farm economy which came to depend on exporting farm products, chiefly cotton for textiles, to England. They wanted to buy metal products like farm tools from England which were cheaper because (a) England was technically ahead and could make tools cheaper and (b) England had cheaper labor. US factories wanted protective tariffs, Northern states had the most industry so they pushed for tariffs. South wanted to buy cheaper so did not want tariffs, or at least high tariffs. No income tax then and most of tax revenue came from tariffs. Problem came up when tariffs got high enough to keep people from buying imports. North wanted high enough tariffs to keep most foreign imports out. This was one of the conflicts which led to the Civil War. The income tax law in 1913 brought in huge amounts of tax money and tariffs were a less important part of the federal budget. World War II came along and Europe and Japan were devastated. Both wanted trade to pay for things they needed. The US, which had financed the war for its allies, wanted a prosperous Europe which could take care of itself and could afford to buy US products. Hidh tariff interferred with this, "free trade" became the policy.
This is a HUGE oversimplifacation but some aspects of the present situation look like history repeating itself.
KEH