"The economic effects of the U.S. trade deficit have been a topic of long-standing congressional interest. The U.S. Constitution grants authority to Congress to regulate commerce with foreign nations and to lay and collect duties, and Congress exercises this authority in numerous ways. These include oversight of trade policy and consideration of legislation to implement trade agreements and to authorize trade programs. In some cases, Congress has delegated certain authorities over trade policy to the Executive Branch: for example, to facilitate trade negotiations."
CRS Report for Congress, R45243