War with Canada · Law and Institutions

Tariff Power After the IEEPA Decision

Congress holds the constitutional tariff power. The present dispute concerns the scope of a 1930 delegation expressly addressing duties.

UPDATED AUGUST 23, 2026 · FAST-MOVING MATTER

Article I empowers Congress to lay duties and regulate foreign commerce. A President may impose tariffs only within authority Congress has delegated. The administration’s current theory rests on Section 338—not on emergency power.

ConstitutionCongressional duties and foreign-commerce powers
19 U.S.C. § 1338Findings, public interest, offset, 50% ceiling, 30-day delay
ProclamationsPresidential findings and product annexes
HTSUS / CBPClassification and entry administration
Judicial reviewStatutory fit, procedure, remedy, and constitutional limits

What Section 338 authorizes

19 U.S.C. § 1338 permits additional duties after specified findings that foreign treatment places U.S. commerce at a disadvantage. The proclaimed duties must “offset” the burden or disadvantage, may not exceed 50 percent ad valorem, and may not take effect earlier than 30 days after proclamation. The statute also addresses suspension, amendment, revocation, recommendations by the International Trade Commission, and possible exclusion of products if discrimination persists or increases.

Why Learning Resources matters

In Learning Resources, Inc. v. Trump, decided February 20, 2026, the Supreme Court held that IEEPA does not authorize presidential tariffs. That decision does not decide Section 338, which expressly speaks of duties. It does reinforce the need to identify the precise delegation and test the challenged action against its statutory limits.

Five unresolved questions

  1. Does the alleged Canadian conduct fit the forms of discrimination or unequal imposition identified in Section 338?
  2. Does a 50 percent duty on each broad product basket “offset” the burden found, or exceed it?
  3. What role must the U.S. International Trade Commission play before presidential action?
  4. How does Section 338 interact with USMCA commitments and dispute-settlement procedures?
  5. Would an exceptionally broad reading create major-questions or nondelegation concerns?
Legal-status discipline. These are potential arguments, not holdings. Do not state that Section 338 is unconstitutional or that the new tariffs are unlawful unless a court so rules.

Primary legal sources

Public education and legal research only. Tariff liability depends on classification, origin, entry date, valuation, content rules, exclusions, foreign-trade-zone status, and later official guidance. Verify the current HTSUS and customs instructions before operational reliance.