By giving the President the power to negotiate agreements, Congress effectively ceded some of his power (authorized under the U.S. Constitution, Article I, Section VIII) to the executive. The president had to consider the well-being of all Americans, his foreign policy priorities, and what was feasible with other countries in his tariff decisions. These considerations have generally left presidents more inclined to cut tariffs than Congress.  Whether Roosevelt or Congress anticipated this outcome is a matter of historical debate. President Franklin D. Roosevelt signed the Reciprocal Trade Agreements Act (RTAA) in 1934. It gave the president the power to negotiate bilateral and reciprocal trade agreements with other countries and allowed Roosevelt to liberalize U.S. trade policy around the world. It is widely attributed that it use opened the era of liberal trade policy, which lasted throughout the twentieth century.  When U.S. tariffs fell dramatically, global markets were also increasingly liberalized.
World trade has grown rapidly. The RTAA was a U.S. law, but offered the first generalized system of guidelines for bilateral trade agreements. The United States and European nations began to avoid a “Beggar thy Neighbour” policy pursuing domestic trade goals at the expense of other nations. Instead, countries began to realize the benefits of trade cooperation. After the Civil War, Democrats were generally in favor of trade liberalization and Republicans in general favor of higher tariffs. The pattern was clear in congressional votes for tariffs from 1860 to 1930. Between the Civil War and Roosevelt`s election, Democrats were the minority in Congress in the majority of Congresses. During their short period of majority, the Democrats passed several tariff-cutting laws. The Wilson-Gorman Act of 1894 and the Underwood Tariff Act of 1913 are examples, but the Republican majorities that followed kept reversing unilateral tariff cuts.
 The U.S. State Department also appreciated the expansion of free trade after World War II. Many at the State Department saw multilateral trade agreements as a way to engage the world in accordance with the Marshall Plan and the Monroe Doctrine. U.S. trade policy has become an integral part of U.S. foreign policy. This pursuit of free trade as diplomacy intensified during the Cold War, when the United States competed with the Soviet Union for relations around the world.  Under the leadership of the United States and the United Kingdom, international cooperation flourished and concrete institutions were created. . . .