• Supreme Court justices express doubts over Trump's use of tariffs under IEEPA.
• Potential ruling against Trump's tariffs could reshape executive authority in trade.
• Discussions include implications of the "major questions" doctrine and congressional powers.
• Trade experts predict uncertainty in tariff policies regardless of the ruling outcome.
• Refund issues could arise if tariffs are ruled illegal, affecting businesses nationwide.

The U.S. Supreme Court is evaluating the legality of President Donald Trump's sweeping tariffs, as justices expressed skepticism about the use of the International Emergency Economic Powers Act (IEEPA) during oral arguments. The president invoked this 1977 law to impose tariffs to combat what he described as national security threats related to trade deficits, yet the justices raised concerns over whether this statute allows for such taxation, noting that it does not explicitly mention tariffs, according to Channel News Asia and India Times.

During the hearing, both conservative and liberal justices challenged U.S. Solicitor General D. John Sauer on whether such tariffs exceeded Trump's authority, given that Congress is constitutionally vested with the power to enforce tax measures. Chief Justice John Roberts highlighted that tariffs appear to function as taxes, which is a core power of Congress, as mentioned by ABC News and Reuters.

The Supreme Court's "major questions" doctrine has emerged as a pivotal concern. This legal principle requires that executive actions of significant economic and political dimensions receive explicit congressional authorization. Since the Trump administration's tariffs could potentially fall under this doctrine due to their magnitude, justices have suggested that a ruling against Trump might align with past applications of this doctrine used to block initiatives from the Biden administration, according to Al Jazeera and Reuters.

Experts are concerned about the economic implications of a ruling against Trump, anticipating increased trade uncertainty regardless of the outcome. They suggest that businesses are still in the dark regarding the process for potential refunds of tariffs that have already yielded substantial revenue to the U.S. Treasury, estimated at around $89 billion from taxes imposed on imports. Any adverse ruling is feared to complicate the process of refunds, creating further unpredictability for businesses engaged in trade, as seen in discussions following the oral arguments, according to CBS News and Reuters.

While the Trump administration may pivot to other legal avenues to preserve tariffs, such as invoking other existing statutes, a loss at the Supreme Court would still represent a major setback to Trump's economic strategy, as further analyzed in Channel News Asia and CBS News.