From Jerry Pournelle, one of my favorite Science Fiction writers,
When I was growing up we were taught in sixth grade that Democrats wanted “tariff for revenue only;” Republicans wanted protective tariff to keep manufacturing – and jobs – at home. Abraham Lincoln said of tariff, if he buys a shirt from England, he gets the shirt but the money leaves the country and pays wages to Englishmen; if he buys it from a US manufacturer, he has the shirt, and the money stays in America, paying American workers. This is, according to Ricardo, far too simple an analysis; but it appeals to reason. American goods may cost more without overseas competition, but the money and jobs stay/ cheaper goods are not always appealing to those who have no jobs to give then wages, and must rely in government to pay them for not working; and a sizeable number of “workers” resent being on the unemployment role and getting welfare aid.
The US establishment went to war in 1940, and suddenly produced tanks, rifles, airplanes, trucks, bandages, ammunition, cargo ships and battleships; when the American people rose up they drowned Germany and Japan in war materiel. The German war machine used animal drawn transport to supply much of the Wehrmacht; The United States turned the last cavalry regiments into mechanized units and the Red Ball Express that supplied Patton. I used mules to plow cotton fields during World War II; but our soldiers did not depend on mules for ammunition. If all our plants had been in Frankfurt instead of Detroit, the outcome might have been different.
That, I believe, is how Trump sees things.