WASHINGTON — The Supreme Court, led by Chief Justice John G. Roberts Jr., delivered a series of rulings this year that both affirmed and restricted presidential authority under President Donald Trump. Throughout his second year in office, the justices navigated complex questions about the limits of executive power, resulting in several notable decisions that curbed the administration’s broader claims.

In a key ruling, the court struck down Trump’s imposition of worldwide tariffs, holding that such economic measures fall under the exclusive purview of Congress rather than the president. This decision underscored the constitutional separation of powers regarding trade and taxation policies.

Another significant judgment invalidated the president’s executive order aimed at ending birthright citizenship. Chief Justice Roberts emphasized that the Constitution explicitly guarantees citizenship to those born on American soil, and the president lacks the authority to override that provision through executive decree.

The court further ruled against the president’s attempt to deploy National Guard troops to the streets of Chicago, determining that such a move exceeded presidential power.

These decisions were met with strong opposition from conservative justices Clarence Thomas and Samuel A. Alito Jr., with Justice Neil M. Gorsuch siding with them in two of the cases. Conversely, the three liberal justices dissented vigorously in instances where the court approved the administration’s actions, including rulings that allowed the termination of Temporary Protected Status (TPS) for Haitian and Syrian nationals and permitted the president to replace key officials leading semi-independent federal agencies.

While the court handed some victories to the Trump administration, such as upholding the ability to end TPS designations and reorganize agency leadership, it simultaneously curtailed assertions of unchecked executive power. The Supreme Court’s mixed decisions this term reflect a nuanced judicial approach to balancing presidential authority with constitutional constraints.