A federal judge in Seattle on Thursday temporarily blocked President Donald Trump’s executive order seeking to end birthright citizenship.

U.S. District Court Judge John Coughenour’s ruling in a case brought by Washington and three other states is the first in what is sure to be a long legal fight over the order’s constitutionality.

Coughenour called the order “blatantly unconstitutional.” 

“I have difficulty understanding how a member of the bar could state unequivocally that is a constitutional order,” the judge told the Trump administration’s attorney. “It boggles my mind.” 

Coughenour’s decision came after 25 minutes of arguments between attorneys for Washington state and the Department of Justice. 

On Tuesday, Attorney General Nick Brown, along with peers in Oregon, Arizona and Illinois, sued the Trump administration over the order. Shortly after filing the lawsuit, the states asked Coughenour to grant a temporary restraining order stopping the executive action from taking effect. 

Eighteen other states filed a similar lawsuit in federal court in Massachusetts. Those states haven’t filed for a preliminary injunction. 

Trump signed the executive order shortly after he was sworn into office on Monday. It would end birthright citizenship for babies born to a mother and father who are not U.S. citizens or lawful permanent residents.

Brett Shumate, of the Department of Justice, argued the rush for an emergency pause is unwarranted because the order doesn’t go into effect until Feb. 19. He called the state’s motion “extraordinary.”

Attorneys for the state acknowledged the temporary restraining order is extraordinary, but warranted. Washington would lose federal dollars used to provide services to citizens and officials would be forced to modify those service systems.

The order is “causing immediate widespread and severe harm,” said Lane Polozola, of the Washington attorney general’s office. “Citizens are being stripped of their most foundational right, which is the right to have rights.” 

The 14th Amendment to the U.S. Constitution codified birthright citizenship in 1868. It begins: “All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.”

The executive order focuses on the “subject to the jurisdiction thereof” phrase.

“The Fourteenth Amendment has never been interpreted to extend citizenship universally to everyone born within the United States,” Trump’s order reads. “The Fourteenth Amendment has always excluded from birthright citizenship persons who were born in the United States but not ‘subject to the jurisdiction thereof.’”

Polozola called this interpretation “absurd” and that birthright citizenship is a right that is “off limits.”

Legal precedent has long backed up birthright citizenship. In 1898, the U.S. Supreme Court upheld the concept when justices ruled Wong Kim Ark, a man born in San Francisco to Chinese parents, was a U.S. citizen.

Coughenour has been a federal judge for decades. Republican President Ronald Reagan nominated him for the bench in 1981. 

Video and audio recording were not allowed in the courtroom Thursday.

Looking forward, the 9th U.S. Circuit Court of Appeals would have jurisdiction over the case. Democratic presidents appointed a majority of the circuit court’s judges. But appeals could also eventually land the dispute before the U.S. Supreme Court.