A US federal judge in Maryland has issued a preliminary injunction blocking President Donald Trump's second executive order on birthright citizenship, dealing another legal blow to one of the administration's signature immigration goals. District Judge Deborah Boardman ruled on Wednesday that the August 6 order was "almost certainly unconstitutional", citing a Supreme Court decision earlier this year that had already struck down Trump's first attempt on the same grounds.

The new executive order took a different approach from its predecessor, targeting what Trump has called "birth tourism" — the practice of travelling to the United States specifically to give birth and secure citizenship for a child. It sought to deny citizenship in four broad categories: children of those accused of entering the country under the guise of tourism to obtain citizenship; children of people classified as "alien enemies", including members of foreign organisations designated as terrorist groups; children of a wider class of foreign diplomatic staff than previously excluded under US law; and children born through surrogacy arrangements entered into for the same purpose. Trump's first order had sought to deny citizenship to children born to undocumented immigrants or those on temporary visas.

Boardman rejected the administration's argument that the legal challenge was premature because federal agencies had not yet issued guidance on how to enforce the order. "No matter what the guidance says, the 2026 Executive Order commands agencies to deny citizenship documents to several broad categories of children," she wrote. Her ruling bars agencies including the Department of State, the Department of Homeland Security, and the Social Security Administration from interfering with or denying citizenship to children covered by the class action lawsuit brought by immigrant rights advocates and affected families.

The legal backdrop is the Fourteenth Amendment to the US Constitution, ratified in 1868, which guarantees citizenship to nearly all persons born on American soil — a right known as birthright citizenship. The constitutional basis has been affirmed in several Supreme Court rulings, most notably in the 1898 case United States v Wong Kim Ark. In June, the Supreme Court ruled six to three in Barbara v Trump that Trump's first executive order violated this clause, a decision Boardman cited directly. "The Supreme Court has spoken: children in the certified class are 'citizens at birth'," she wrote.

The ruling was welcomed by immigrant rights organisations. "When it comes to attacking birthright citizenship, the Trump administration has lost before this court, lost before the Supreme Court, and lost again today," said Shana Khader, Legal Director at We Are CASA, a Maryland-based advocacy group. The case underscores a broader pattern: Trump's aggressive immigration agenda — which also includes mass deportation efforts and the removal of protections for nationals of numerous countries — continues to face sustained resistance in federal courts. Despite repeated legal defeats on this specific issue, the administration has signalled it intends to keep exploring avenues to challenge the constitutional framework underpinning birthright citizenship.