A tariff, or the imposition of taxes on imports into America, has historically been a very important form of taxation in America. This type of taxation has crucial merits, for instance, by protecting domestic labor and capital investment, by maintaining domestic sustainability in certain industries, as well as protection from foreign "dumping" of goods onto our land. The importance of import duties to historical America, is demonstrated quite strongly by the visceral reaction of domestic tea merchants in America, when England's East Indian company was allowed by British parliament to sell its tea directly to America, thereby significantly undercutting the price of tea in America, because the East Indian company was permitted a special exemption for not paying import duties in England, whereas the colonists were subject to these duties for their tea by parliament. Therefore this inherent unfairness in the implementation of taxation/tariffs was the immediate cause of the "Boston Tea Party".
According to progressive-economy.org, in 1912 30% of the income derived by the Federal Government came from tariffs, whereas 100 years later, tariffs in America average around 1.7%. While there is a lot to be said about having "open borders" in regards to goods, both exported as well as imported, the reduction of tariffs or the elimination of them therewith, clearly, by definition, will change who the winners are as well as who the losers are everywhere that international trade exists. In fairness, to virtually any domestic manufacturer of goods in America, their labor, insurance, property, and other associated costs, will invariably be higher than most other non-first world countries, so that the only possible way that American companies that produce goods domestically can be competitive against foreign competitors would be only in their inherent advantages of lower transportation costs, knowhow, and machinery. When it comes to machinery, however, and to some degree, knowhow, these too can be exported to foreign countries, effectively giving those foreign countries the final means necessary to undercut domestic competition.
As previously stated, the elimination or the lowering of tariffs obviously brings benefits to certain parties and industries within America. For instance, as a consumer, you, for a certainty, will pay a lower price for goods than you would do with the imposition of duties, although there is always the chance that over time this will not be true, when, for instance, foreign countries are able to gain essentially monopoly or duopoly power on the basis of your exit from the business as a competitor, but overall, clearly a no tariff policy, saves American consumers money. Additionally, the domestic manufacturers of equipment that is exported around the world are definitely beneficiaries of open markets because their market share has increased significantly from just our borders, international financiers too benefit from the loaning of money and capital while being pay fees and interest for having done so, and certain, specific industries or knowhow, that are sufficiently advanced or that take a tremendous amount of capital investment and technological skill, are typically protected quite well from foreign competition because there essentially isn't any meaningful competition to them.
Americans rightly wonder what has happened over the last few decades to the "blue collar" worker in America. Apparently, his work is increasingly being accomplished overseas, leaving our people underemployed and dependent upon government for necessary handouts. It is critical to understand that if multi-national corporations and foreign companies are continually enabled to exploit cheap labor and resources overseas, yet at the same time, suffer no consequences from import duties to America that this policy will eviscerate the noble, working man in America, and turn these men into serfs, without hope, without property, and without a future.