The states, led by New Jersey, said Trump lacks the power to override protections enshrined in the citizenship clause of the 14th Amendment that confer citizenship on anyone born in the U.S. and subject to its jurisdiction.
The states allege that Trump's executive order limiting birthright citizenship violates the Constitution. (AP Photo/Evan Vucci)
The executive order, slated to go into effect within 30 days, would apply to children born to mothers who are unlawfully present, and whose fathers are not U.S. citizens or lawful permanent residents. It would also apply to children born to mothers who are lawfully present in the U.S. at the time of a child's birth but only temporarily, such as those present on tourist, work or student visas.
The states attributed the executive order to Trump's stated goal of deterring immigration to the U.S., but said the Constitution doesn't allow the president or Congress to control who gets citizenship as a policy option for addressing immigration issues.
The judicial and executive branches have for more than a century affirmed and understood that the citizenship clause confers citizenship to all children born in the U.S., the states argued.
The states are asking the court to immediately block the executive order during litigation, saying children born when the order takes effect will otherwise be both deportable and stateless.
The other plaintiff states are New York, California, Colorado, Connecticut, Delaware, Hawaii, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nevada, New Mexico, North Carolina, Rhode Island, Vermont and Wisconsin.
New Jersey Attorney General Matthew Platkin said Tuesday's lawsuit should send a message to the Trump administration that states are primed and ready to take the president to court.
"President Trump's attempt to unilaterally end birthright citizenship is a flagrant violation of our Constitution," Platkin said. "For more than 150 years, our country has followed the same basic rule: babies who are born in this country are American citizens."
The U.S. Department of Justice and the White House did not immediately return requests for comment.
Washington, Arizona, Illinois and Oregon filed their own challenge to the executive order on Tuesday afternoon in Washington federal court.
Washington Attorney General Nick Brown said the state had its own unique interests that warranted filing a separate suit, suggesting that interest lies in the loss of federal funding for health and education services.
"By purporting to unilaterally strip citizenship from individuals born in the plaintiff states based on their parents' citizenship or immigration status, the plaintiff states will be forced to bear significantly increased costs to operate and fund programs that ensure the health and well-being of their residents," the four states said in their suit.
During a press conference, Brown — who was sworn in earlier this month — said he doesn't plan to challenge every Trump action, but this one was worth bringing because the president's executive order "is so plainly and obviously illegal ... and un-American."
"I think it is scary that the president would come in and try to undermine so much of what has been foundational to America," Brown said.
The states are represented by their respective attorneys general.
Counsel information for the federal government was not immediately available.
The cases are State of New Jersey et al. v. Trump et al., case number 1:25-cv-10139, in the U.S. District Court for the District of Massachusetts, and State of Washington et al. v. Trump et al., case number 2:25-cv-00127, in the U.S. District Court for the Western District of Washington.
--Editing by Marygrace Anderson.
Update: This story has been updated with additional information.