A federal judge on Thursday issued a temporary restraining order against President Donald Trump’s executive order redefining birthright citizenship, describing it as “blatantly unconstitutional.”

The decision marks the first major legal challenge to the order, which is part of a multi-state effort involving 22 states and immigrant rights organizations.

U.S. District Judge John Coughenour, who has served on the bench for over 40 years and was appointed by President Ronald Reagan, presided over the hearing in Seattle.

During the session, Coughenour repeatedly questioned the constitutionality of the executive order.

Addressing Justice Department attorney Brett Shumate, the judge said, “This is a blatantly unconstitutional order,” adding that he could not recall another case where the challenged action was so clearly at odds with the Constitution.

The executive order, signed by Trump on Inauguration Day, seeks to deny citizenship to children born in the United States to noncitizen parents.

It is scheduled to take effect on February 19 and could affect hundreds of thousands of people born in the U.S., according to lawsuits challenging the order.

The temporary restraining order issued by Judge Coughenour applies nationwide.

The case heard on Thursday is one of five lawsuits filed against the executive order.

Four states—Arizona, Illinois, Oregon, and Washington—brought the suit that was considered in the Seattle hearing.

The legal challenges argue that the order violates the 14th Amendment to the U.S. Constitution, which guarantees citizenship to all individuals born or naturalized in the United States.

The 14th Amendment, ratified in 1868, states: “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.”

This principle, known as jus soli or “right of the soil,” is the foundation of birthright citizenship in the U.S. and about 30 other countries, including Canada and Mexico.

The lawsuits also include testimonies from attorneys general who are U.S. citizens by birthright, as well as accounts from individuals who fear the order will deny citizenship to their children.

One case highlights the story of “Carmen,” a pregnant woman who has lived in the U.S. for over 15 years and is awaiting permanent residency.

Carmen’s legal team argues that her child would face serious harm if denied citizenship.

The Trump administration contends that the executive order does not violate the Constitution.

Administration lawyers argue that the order only applies to children born after February 19 and does not retroactively affect individuals already granted citizenship.

They also claim that states lack the standing to sue because no harm has occurred yet.

Trump’s executive order asserts that children born to noncitizen parents are not subject to U.S. jurisdiction and therefore do not qualify for citizenship.

However, opponents point to the 1898 Supreme Court case of United States v. Wong Kim Ark, which upheld that individuals born in the U.S. are citizens, even if their parents are not.

In that case, the court ruled that Wong Kim Ark, born in San Francisco to Chinese immigrants, was a U.S. citizen despite the restrictions of the Chinese Exclusion Act.

If implemented, Trump’s order could significantly impact children born in the U.S. to undocumented parents.

According to a lawsuit filed in Seattle, approximately 255,000 citizen children were born to mothers living in the country without documentation in 2022, with 153,000 of those births involving two undocumented parents.

The order has sparked widespread backlash from state officials and immigrant rights advocates.

Connecticut Attorney General William Tong, the first Chinese American elected as an attorney general in the U.S., has been outspoken in his opposition.

“There is no legitimate legal debate on this question,” Tong said.

“But the fact that Trump is dead wrong will not prevent him from inflicting serious harm right now on American families like my own.”

While Thursday’s restraining order temporarily halts the executive order, the legal battle is expected to continue.

The outcome could have far-reaching consequences for the interpretation of the 14th Amendment and the future of birthright citizenship in the United States.