Congress gave away the power. That is the short version of how the United States arrived at an average tariff rate of 27% by mid-April 2025 — a level not seen since the Smoot-Hawley era a century ago. The longer version involves a specific piece of Cold War legislation, the 1962 Trade Expansion Act, and a section of it that has quietly sat on the books for decades.
Section 232 of that law lets a president raise tariffs unilaterally if the stated reason is national security. No vote in Congress. No debate on the floor. Just a determination from the White House that imported steel or aluminum or cars threatens the country’s defense industrial base. President Trump invoked that authority to push tariffs as high as 50% on cars, steel, aluminum, copper, and what the administration calls “derivative products” — the things made from those metals.
The constitutional baseline is clear enough. Article I, Section 8 gives Congress the sole authority to levy taxes, and tariffs are taxes on imports. But Congress wrote Section 232, and later Congresses left it in place. Over two months in early 2025, the average effective tariff rate jumped from 2.5% to 27%. That is the arithmetic of a president using authority Congress handed him, not one he seized.
Metals and metal-made items took the heaviest hits. So did vehicles. The list of products under consideration for new tariffs keeps growing. Large-scale batteries. Cast iron and iron fittings. Plastic piping. Industrial chemicals. Power grid equipment. Telecom gear. The administration has not finished the work.
The stated rationale is national security. Exactly how imported plastic piping or telecom equipment threatens national security has been the subject of ongoing discussion and analysis, as the official language puts it. The report does not provide a detailed justification, and none is available in the source material. What is known is that the legal mechanism exists, it has been used, and the tariff rates have gone up across the board.
The economic consequences are not theoretical. A 27% average tariff rate means the cost of imported goods has risen sharply for American businesses that buy foreign inputs. Those costs get passed along. The sectors most exposed — metals, vehicles, the industries that rely on them — are already adjusting. The report notes the tariffs have sparked considerable interest and debate about what this means for the US economy and trade relationships. That is a restrained way of putting it.
Trade partners are watching. Some have their own legal options. Others are simply waiting to see if the tariff list expands further. The report lists batteries, fittings, piping, chemicals, and telecom equipment as items being considered. That suggests the administration sees this as an ongoing process, not a finished one.
The constitutional question — whether Congress can delegate its taxing power to the president through a national security exception — is old. The 1962 act predates the current trade environment by more than sixty years. It was written for a different world. But it is the law, and it is being used. The average tariff rate has moved from 2.5% to 27% in roughly three months. That is the fact on the ground.
