Trade policy expert Scott Lincicome famously (among economists, at least) coined the phrase (which was made into a t-shirt):
Tariffs Not Only Impose Immense Economic Costs but Also Fail to Achieve Their Primary Policy Aims and Foster Political Dysfunction Along the Way
What this means is that tariffs increase costs, either to other producers or eventually to consumers, which reduces the flow of cash to other productive uses, which ultimately increases inflation and harms productivity. Tariffs -- a form of central economic planning, aka, "socialism" -- harm economic growth.
Some of the current inflation we face now is the result of tariffs imposed over the past four years.
And they are hurting the domestic production of other goods. A current example is the harm tariffs have imposed on nail manufacturers, who have been forced to pay more for steel.
Rather than eliminate tariffs on steel, however, the U.S. trade policy position is that other countries that produce nails are selling their nails too inexpensively so imported nails should be taxed at a higher rate.
Third, the case shows how “injury” to a domestic industry is often blamed on foreign competition but is actually the result of bad U.S. policy. In particular, the U.S. government has spent the last four years working to increase the domestic price of steel (nails’ only major input) via tariffs under Section 232 of the Trade Expansion Act of 1962. As discussed here last year, the tariffs quickly increased U.S. steel prices far above the prices of the same materials abroad, thus undermining steel-consuming manufacturers’ competitiveness versus their foreign counterparts. In this case, the tariffs made American-made nails more expensive—a fact that Mid Continent Nail (the company petitioning for these AD/CVDs on nail imports) itself confirmed. In particular, the company experienced direct cost increases of 25 percent resulting from the Section 232 tariffs, 19 percent of which it passed on to its customers.
Protectionism isn't good for American consumers nor is it good for American workers. If we want to put America first again, we will reduce and eliminate tariffs on imported goods and let the free market flourish.
