On May 30, 2019 President Trump announced via Twitter that the United States (U.S.) will impose tariffs on Mexican imports to prompt Mexico to significantly reduce immigration to the U.S. President Trump will impose these additional tariffs in the context of rapidly increasing immigration from Mexico to the U.S. over the past months.
In declaring these new tariffs, President Trump relied on powers that Congress delegated to the president under the International Emergency Economic Powers Act (IEEPA) of 1977. Congress enacted this statute to provide the president with the necessary authority to restrict transactions between U.S. persons and foreign entities located outside the U.S. that pose threats to U.S. national security interests. Therefore, the president typically invokes IEEPA in sanctions matters (e.g. the Iranian, Syrian, and North Korean sanctions programs) and export control matters (e.g. regulations regarding transferring control of sensitive technology and information from a U.S. person to a foreign person).
The absence of language in IEEPA referring to “tariffs” or “immigration” combined with the stark contrast between this current invocation and past invocations of IEEPA have lead some scholars to believe that the use of this statute for imposing additional tariffs on Mexican imports may be illegal. Members of President Trump’s own political party have expressed similar beliefs. For instance, Chuck Grassley, a Republican senator on the U.S. Finance Committee, has publically supported this view by saying that President Trump has exceeded his authority.