I will do my best to make this brief and simple as I think it is important that as many people read and understand it as possible.
The standard Libertarian/Conservative response to the suggestion of tariffs is that it will create inefficiencies in trade. Any concussed football player who has attended at least one full lecture of basic Microeconomics can tell you that. The difference between the ideal Microeconomic circumstance of individuals trading without barrier and reality, is that the industry, in the US, is hampered by taxes, technical regulations, and worker safety standards (not to mention beholden to union standards). These regulations make it more difficult to and costly to produce things like steel and aluminum (commodities on which Trump recently proposed placing tariffs).
Whether you believe the majority of these standards and regulations are necessary or not, it is undeniable that, all other things equal, they make it more expensive to produce everything in this country. Also, regardless of whether you believe these standards and regulations are necessary or not, they are not going away anytime soon. There is too much money, man power, and public sentiment behind maintaining them as they are. With all of these restrictions in place, it becomes much less expensive to purchase raw materials as well as finished products from over seas.
Once financial resources leave the country, they do not return. It is often said that America needs to transition into a “service economy,” which would be fine if our services were in demand from the countries like China and India. They aren’t. There is no demand for American software expertise in India. The Chinese are not employing American lawyers and accountants. As it stands, unrestricted “free trade” of physical goods is a one way conveyor belt of financial resources out of this country.
The solution which balances out the disparity in production costs between domestic and foreign products and prevents American workers from losing their jobs is tariffs. If tariffs are not instituted, it will become impossible for the products of American industry and American workers to compete with commodities produced in places like China and India, which have little to no value of human life at all, let alone safety regulations or worker protections. Reasonable tariffs will protect American industry and American jobs.