The RTAA, which was temporarily updated until 1961, is a multilateral trade negotiation at GATT and negotiations with new Member States.  The U.S. State Department also found good use of free trade expansion after World War II. Many in the Department of Foreign Affairs saw multilateral trade agreements as a means of integrating 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 search for free trade as diplomacy intensified during the Cold War, when the United States competed with the Soviet Union for relations around the world.  RTAA`s innovative approach freed Roosevelt and Congress from breaking this trend of tariff increases. It has linked U.S. tariff reductions to reciprocal tariff reductions with international partners. It also allowed Congress to approve tariffs by a simple majority, unlike the two-thirds majority needed for other contracts.
In addition, the President had the power to negotiate the terms. The three innovations in trade policy have created the political will and feasibility of a more liberal trade policy.  The Reciprocal Trade Agreements Act provides the President with a mechanism: when U.S. tariffs fell dramatically, global markets were also increasingly liberalized. Global trade has undergone a rapid transformation. The RTAA was a U.S. law, but it provided the first widely used system of guidelines for bilateral trade agreements. The United States and European nations began to avoid beggar neighborhood policies that pursued national trade objectives at the expense of other nations. Instead, countries have begun to realize the benefits of trade cooperation. Democrats voted much more in favor of trade liberalization than Republicans, but were not consistent in their preferences. Mp Henry Rainey (D-IL) and members of Roosevelt`s government, Rexford Tugwell, Raymond Moley and Adolf Berle, were skeptical of tariff reductions during the Depression. However, the government decided to use a Democratic-controlled congress and presidency to impose the RTAA.
In 1936 and 1940, the Republican Party ran on a platform to lift tariff reductions guaranteed under the RTAA. But when they reclaimed Congress in 1946, they did not act to remove tariffs. In the years since the adoption of the RTAA in 1934, the economies of Europe and East Asia had been decimated by the violence of World War II, which left a huge global production gap filled by American exporters.  During the war, the United States had the highest positive balance in its history. Republican preferences for tariffs began to shift as exporters in the home districts began to benefit from stronger international trade. In the 1950s, there was no statistically significant difference between Republicans and Democrats on customs policy, a change that has lasted ever since.  After the Civil War, Democrats were generally in favour of trade liberalization and Republicans in general favored higher tariffs.