Assessing the economic impact of trade agreements is a difficult task due to the lack of data and important theoretical and practical questions related to achieving economic outcomes. In addition, such estimates provide an incomplete assessment of the overall economic impact of trade agreements40.40 Many studies indicate that NAFTA has achieved many trade and economic benefits.41 Other studies indicate that NAFTA has generated some cost to U.S. workers42. but that there are both winners and losers of adaptations. USCAIP, which is managed by the North American Development Bank, provides financial assistance to municipalities that have experienced significant job losses as a result of changes in the pattern of trade with Mexico or Canada as a result of NAFTA. NAFTA influenced other U.S.-negotiated free trade agreements thereafter and also influenced multilateral negotiations. Nafta has launched a new generation of trade agreements in the Western Hemisphere and other parts of the world and has influenced negotiations in areas such as market access, rules of origin, intellectual property rights, foreign investment, dispute resolution, workers` rights and environmental protection. The United States currently has 14 free trade agreements with 20 countries. As with NAFTA, these trade agreements have often been supported or criticized by similar employment arguments. After the election of President Trump in 2016, support for NAFTA was highly polarized between Republicans and Democrats.
Donald Trump has expressed a negative view of NAFTA, calling it “the worst trade deal ever adopted in this country.”  Republican support for NAFTA has grown from 43% in 2008 to 34% in 2017. Meanwhile, Democrats` support for NAFTA has grown from 41 percent in 2008 to 71 percent in 2017.  From the first round, agriculture has been a controversial issue within NAFTA, as has been the case with almost all free trade agreements signed under the WTO.