https://www.supremecourt.gov/opinions/2 ... 7_4gcj.pdf
THE CHIEF JUSTICE delivered the opinion of the Court with respect to Part II–B, concluding:
(a) IEEPA authorizes the President to “investigate, block during the pendency of an investigation, regulate, direct and compel, nullify, void, prevent or prohibit . . . importation or exportation.” §1702(a)(1)(B). Absent from this lengthy list of specific powers is any mention of tariffs or duties. Had Congress intended to convey the distinct and extraordinary power to impose tariffs, it would have done so expressly, as it consistently has in other tariff statutes.
The power to “regulate . . . importation” does not fill that void. The term “regulate,” as ordinarily used, means to “fix, establish, or control; to adjust by rule, method, or established mode; to direct by rule or restriction; to subject to governing principles or laws.” Black’s Law Dictionary 1156. The facial breadth of this definition places in stark relief what ”regulate” is not usually thought to include: taxation. Many statutes grant the Executive the power to “regulate.” Yet the Government cannot identify any statute in which the power to regulate includes the power to tax. The Court is therefore skeptical that in IEEPA—and IEEPA alone—Congress hid a delegation of its birth-right power to tax within the quotidian power to “regulate.”
While taxes may accomplish regulatory ends, it does not follow that the power to regulate includes the power to tax as a means of regulation. Indeed, when Congress addresses both the power to regulate and the power to tax, it does so separately and expressly. That it did not do so here is strong evidence that “regulate” in IEEPA does not include taxation.
A contrary reading would render IEEPA partly unconstitutional. IEEPA authorizes the President to “regulate . . . importation or exportation.” §1702(a)(1)(B). But taxing exports is expressly forbidden by the Constitution. Art. I, §9, cl. 5.
The “neighboring words” with which “regulate” “is associated” also suggest that Congress did not intend for “regulate” to include the revenue-raising power. United States v. Williams, 553 U. S. 285, 294. Each of the nine verbs in §1702(a)(1)(B) authorizes a distinct action a President might take in sanctioning foreign actors or controlling domestic actors engaged in foreign commerce, as Presidential practice confirms. And none of the listed authorities includes the distinct and extraordinary power to raise revenue—a power which no President has ever found in IEEPA. Pp. 14–16.