Blue Brief 2025-2026

opinion , written by Chief Justice Roberts, held that IEEPA does not authorize the imposition of tariffs. But the majority split on the role of the major questions doctrine in reaching that conclusion. The major questions doctrine holds that when an agency or the executive claims broad authority to act on a matter of vast economic or political significance, it must point to clear congressional authorization for that power. The Roberts-Gorsuch-Barrett plurality applied the major questions doctrine to curtail the claimed power. This three-justice decision held that there is no emergency exception to the doctrine and treated as telling the fact that in IEEPA’s fifty-year existence, no President had previously invoked it to impose tariffs.

tools of statutory interpretation, without the major questions doctrine, were sufficient to decide the case. In Kagan’s view, the text of IEEPA, properly read, simply did not reach tariffs. For Kagan, IEEPA is a sanction and asset-control statute — designed to let the President freeze, block, and prohibit foreign linked transactions — and thus nearly the opposite of a statute conferring revenue-raising power over imports. Interestingly, even among the justices who agreed on applying the major questions doctrine, there was disagreement about the doctrine. Justice Gorsuch defended his view of the major questions doctrine as a substantive clear-statement rule designed to protect the vesting of legislative power in the Congress. Responding to criticism from Gorsuch, Justice Barrett reaffirmed her view that the doctrine is an ordinary application of textualism, situated within “commonsense principles of communication.” The principal dissent , authored by Justice Kavanaugh and joined by Justices Thomas and Alito, argued that historical practice, precedent, and the ordinary meaning of the word “regulate” establish that IEEPA authorizes presidential tariffs. Kavanaugh’s dissent also argued against applying the major questions doctrine to a foreign affairs statute. Justice Thomas wrote separately to argue that the nondelegation doctrine — which prohibits broad conferral of policymaking responsibility on the executive — does not apply to foreign trade, suggesting that Congress has substantial authority to delegate tariff-making powers in that domain. This more sweeping constitutional claim went beyond Kavanaugh’s position.

In contrast, Justice Kagan, joined by Justices Sotomayor and Jackson , found that ordinary

The decision’s immediate effect is to invalidate the IEEPA tariffs at the heart of the administration’s trade policy. Its longer term significance will depend on how the Court views any future

expansive claims of executive authority.

UNIVERSITY OF SAN DIEGO SCHOOL OF LAW | Faculty Review of 2025-2026 U.S. Supreme Court Term | Page 30