This paper seeks to explain what factors drove the United States in the era of Donald Trump to carry out economic protectionism. Donald Trump, issued a controversial policy. For examples, The decision of America exit from the Trans Pacific Partnership even increases the import tariff of Chinese products. Using the concept of national interest and the theory of foreign political decision making by William D. Coplin, Trump's American economic protectionist policy was driven by two factors. First, there are demands and pressure on domestic politics in the United States by the domestic industry. The second is a decrease in the economic capacity of the United States in the form of a GDP figure that does not reach 3% and a trade balance deficit with China.