The Constitution gives Congress the ultimate authority "to lay and collect Taxes, Duties, Imposts and Excises" and "to regulate Commerce with foreign Nations." Over time, Congress has delegated some of this power to the executive branch through laws like the Trade Act of 1974, but it retains the ability to reclaim or limit that authority. It's a high bar though; afaik Congress would need a 2/3 majority to override Trump.