The International Emergency Economic Powers Act doesn't authorize President Donald Trump to impose tariffs, the U.S. Supreme Court said Friday in a 6-3 majority opinion striking down duties he imposed on countries across the world under the law and upholding lower court rulings that determined his actions unlawful.

The Supreme Court's 6-3 opinion held that the International Emergency Economic Powers Act does not grant President Donald Trump "the independent power to impose tariffs on imports from any country, of any product, at any rate, for any amount of time." (iStock.com/wildpixel) The U.S. Constitution gives the power to impose taxes and duties to Congress, while the executive branch is afforded no such similar power, particularly during peacetime, Chief Justice John Roberts wrote in the opinion.

The government relied on the words "regulate" and "importation" in the statute to justify Trump's broad use of the IEEPA to impose tariffs, but the majority of the court did not support that argument.

Trump "asserts the independent power to impose tariffs on imports from any country, of any product, at any rate, for any amount of time," Justice Roberts wrote.

"Those words cannot bear such weight," he wrote.

Furthermore, the IEEPA explicitly details several economic powers that the statute authorizes the president to take in response to international emergency, including sanctions and asset freezes, but it makes no mention of tariffs or duties.

"That omission is notable in light of the significant but specific powers Congress did go to the trouble of naming," Justice Roberts wrote in the opinion. "It stands to reason that 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 majority applied the major questions doctrine, which generally says large-scale regulatory initiatives that have broad effects can't be grounded in vague, minor or obscure provisions of law without clear congressional authorization.

Justice Roberts found insufficient the arguments that were raised against applying the doctrine including its application to a matter of foreign affairs, of which the president has unique discretion, and in a matter of a national emergency.

Those arguments were raised by the government and relied on by the lead dissenting opinion, penned by Justice Brett Kavanaugh. According to Justice Kavanaugh's dissent, the language in the IEEPA should be construed broadly to include tariff authority because the statute, although ambiguous on that matter, addresses a significant major question in the form of international emergency powers.

"The sole legal question here is whether, under IEEPA, tariffs are a means to 'regulate ... importation,'" Justice Kavanaugh wrote. "Statutory text, history, and precedent demonstrate that the answer is clearly yes: Like quotas and embargoes, tariffs are a traditional and common tool to regulate importation."

The majority opinion said that kind of interpretation put forth by the government and Justice Kavanaugh would run afoul of constitutional principles, and that Trump is unable to identify any congressional delegation that would afford him the powers he has sought under the IEEPA.

"There is no major questions exception to the major questions doctrine," Justice Roberts wrote.

Justices Amy Coney Barrett and Neil Gorsuch wrote concurring opinions to the majority judgment offering their perspectives on how the major questions doctrine should apply to the case.

Another concurrence, written by Justice Elena Kagan and joined by Justices Sonia Sotomayor and Ketanji Brown Jackson, offered perspective as to why the doctrine shouldn't apply when the statutory language and context is clear that the IEEPA doesn't include authority to impose tariffs.

A concurring opinion by Justice Jackson also supported the idea that applying the major questions doctrine is unnecessary when the statutory language and legislative history make clear the IEEPA wasn't intended to authorize tariffs.

At the Supreme Court, the government was looking to reverse a Federal Circuit ruling in August that largely affirmed a U.S. Court of International Trade judgment deeming certain tariffs under the IEEPA unlawful in a consolidated case challenging the tariffs raised by several small businesses led by V.O.S. Selections Inc. and a dozen states. The government is also arguing that the CIT is the proper venue — as opposed to the federal district courts — for matters involving tariffs imposed under the IEEPA in a case brought by Illinois-based toy-makers Learning Resources Inc. and hand2mind Inc.

The Supreme Court vacated the ruling in the Learning Resources case Friday and remanded it back to the district court with instructions to dismiss the suit for lack of subject matter jurisdiction, finding the CIT to be the proper venue for suits challenging the tariffs imposed under the IEEPA.

The parties challenged the tariffs placed worldwide as part of a national emergency that Trump declared under the IEEPA in April over persistent U.S. trade deficits. The parties have also challenged another set of tariffs under the IEEPA on Chinese, Mexican and Canadian goods in response to a national emergency declared over illegal fentanyl entering the U.S.

During oral arguments in November, several Supreme Court justices appeared skeptical of the government's arguments seeking to salvage Trump's emergency tariffs. Justices including Justice Roberts found it difficult to constitutionally sever the revenue-raising components of the tariffs Trump has imposed under the IEEPA from their regulatory effects.

Oregon Attorney General Dan Rayfield, who led the legal effort on behalf of the states challenging the IEEPA tariffs, said in a statement that the ruling would help lower costs for Americans, who have borne the brunt of the tariff increases Trump has imposed. He thanked Oregon Deputy Attorney General Benjamin Gutman for arguing the case for the states.

"Today, the Supreme Court made it clear that no president gets to levy taxes on Americans disguised as tariffs," Rayfield said. "At a time when we should all be working together to do everything in our power to keep the cost of living down for working families, the president tried to sidestep Congress to increase prices on groceries, utilities, and basic everyday necessities."

Neal Katyal at Milbank LLP, who argued on behalf of the small businesses during the oral arguments, issued a statement following the ruling.

"Today, the U.S. Supreme Court stood up for the rule of law and Americans everywhere," Katyal said. "Its message was simple: Presidents are powerful, but our Constitution is more powerful still. In America, only Congress can impose taxes on the American people."

Katyal thanked the Liberty Justice Center in his statement, the nonprofit firm that led the V.O.S. Selections case. Sara Albrecht, the center's chair, said that the justices' ruling striking down the tariffs leaves more work to be done.

"The Liberty Justice Center's work is just beginning," she said. "We intend to help small businesses navigate the refund process, including developing a centralized database, information portal, and referral network to connect affected companies with qualified attorneys to pursue potential refund claims."

The toy-makers are represented by Pratik A. Shah, James E. Tysse, Matthew R. Nicely, Daniel M. Witkowski, Kristen E. Loveland and Margaret O. Rusconi of Akin Gump Strauss Hauer & Feld LLP.

The businesses are represented by Neal Kumar Katyal, Colleen E. Roh Sinzdak, Ezra P. Louvis and Samantha K. Ilagan of Milbank LLP, by Michael W. McConnell, Steffen N. Johnson and Paul N. Harold of Wilson Sonsini Goodrich & Rosati PC, by Jeffrey M. Schwab, Reilly Stephens and James McQuaid of the Liberty Justice Center and by Ilya Somin of George Mason University's Antonin Scalia Law School.

The states are represented by their attorneys general.

The government is represented by D. John Sauer and by Brett A. Shumate, Sarah M. Harris, Sopan Joshi, Mark R. Freeman, Michael S. Raab, Brad Hinshelwood, Daniel Winik and Sophia Shams of the U.S. Department of Justice's Civil Division.

The cases are Learning Resources Inc. et al. v. Trump et al., case number 24-1287, and Trump et al. v. V.O.S. Selections Inc. et al., case number 25-250, in the Supreme Court of the United States.