I believe that Tariffs were a major source of Federal government operations revenue for nearly 200 years. Apparently, the World Trade Organization (WTO) founders successfully lobbied our elected Congressional bodies to forego that revenue to facilitate International Trade so the WTO sponsors would prosper. More than likely, a significant loan item of the National Debt. In theory, no tariffs could level the playing field of international trade; the reality has been manipulation by WTO members, e.g. off-shoring manufacturing to cheaper labor markets and member state’s lobbied politicians awarding state-sponsored subsidies, issuing tax breaks, etc.