Trump Administration Tariff Actions: Frequently Asked Questions [February 22, 2019] [open pdf - 2MB]
From the Document, "The Constitution grants Congress the sole authority over the regulation of foreign commerce. Over the past several decades, Congress has authorized the President to adjust tariffs and other trade restrictions in certain circumstances through specific trade laws. Using these delegated authorities under three trade laws, President Trump has imposed increased tariffs, largely in the range of 10% - 25%, on a variety of U.S. imports to address concerns related to national security, injury to competing industries, and China's trade practices on forced technology transfer and intellectual property rights, among other issues. Several U.S. trade partners argue that these tariff actions violate existing U.S. commitments under multilateral and bilateral or regional trade agreements and have imposed tariffs on U.S. exports in retaliation. Congress continues to actively examine and debate these tariffs, and several bills have been introduced either to expand, limit, or revise existing authorities."
CRS Report for Congress, R45529
Congressional Research Service: https://crsreports.congress.gov/