On October 20, the US Supreme Court ruled that the tariff increases enacted by former President Donald Trump were illegal. The court's decision came after an appeal from the Department of Justice, challenging a lower court's ruling that found Trump had overstepped his authority by imposing the majority of the global tariffs based on federal emergency legislation. This landmark ruling places significant limitations on a president's power to impose tariffs unilaterally without congressional approval.

The implications of this decision are notably substantial, as it not only curtails the executive's ability to impose tariffs without legislative consent but also directly affects international trade relationships, including measures against countries like Brazil. This ruling potentially alters the landscape of US trade policy and could set a precedent for future administrations regarding the scope of presidential authority in economic matters.

The legal battle surrounding these tariffs has been ongoing since mid-2025, highlighting the contentious nature of trade policy under the Trump administration and the complexities involved in executive actions. With the Supreme Court's ruling, there may be a reevaluation of existing trade agreements and tariff policies, leading to new discussions in Congress about trade authority and its limitations under US law.