The Supreme Court will hear oral arguments on Thursday over President Donald Trump’s emergency request to roll back nationwide injunctions blocking his executive order to end birthright citizenship.

The rare May sitting of the court sets the stage for a decision by this summer on whether Trump can move forward with plans to limit U.S. citizenship only to children born on American soil to lawful permanent residents.

The case is also expected to address the legality of individual district court judges single-handedly blocking a presidential policy nationwide. Trump is seeking to dissolve judicial orders preventing mass federal layoffs, funding freezes, and expedited deportation protocols.

For more than a century, courts and the government have interpreted the 14th Amendment’s citizenship clause to apply to anyone born in the U.S., regardless of the citizenship status of a child’s parents.

The Amendment, ratified after the Civil War, states that 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.”

On his first day in office, Trump signed an executive order unilaterally declaring that only newborns whose parents have permanent legal status are “subject to the jurisdiction” of the U.S. and therefore eligible to be citizens.

“This administration believes that birthright citizenship is unconstitutional,” White House press secretary Karoline Leavitt explained during a February briefing.

Three different sets of plaintiffs sued to block the order, including a group of 22 states, immigrant advocacy groups, and pregnant women whose soon-to-be-born children would be affected.

“Birthright citizenship is at the core of our Nation’s foundational precept that all people born on our soil are created equal, regardless of their parentage,” attorneys for the immigrant advocates wrote in legal briefs.

An estimated 150,000 children are born each year in the U.S. to parents who are not legal permanent residents, according to government data.

“Instead of the right to full participation and belonging in their home country — the United States — these children will be forced to live in the shadow,” the states warned in court filings, “under the constant risk of deportation while the appeals run their course.”

Federal judges in Maryland, Massachusetts and Washington state — and three federal appeals court panels — have issued nationwide injunctions keeping the Trump policy on hold during litigation, concluding that it very likely violates the Constitution and high court precedent.

“I have been on the bench for over four decades. I can’t remember another case where the case presented is as clear as it is here,” said Judge John Coughenour of the Western District of Washington during a January hearing in the case. “This is a blatantly unconstitutional order.”

In 1898, the Supreme Court directly addressed the question of citizenship for children born to non-citizens on U.S. soil, ruling in the landmark case U.S. v Wong Kim Ark that they are Americans under the law.

“The [14th] Amendment, in clear words and in manifest intent, includes the children born, within the territory of the United States, of all other persons, of whatever race or color, domiciled within the United States,” wrote Justice Horace Gray for the 6-2 majority. “Every citizen or subject of another country, while domiciled here, is within the allegiance and the protection, and consequently subject to the jurisdiction, of the United States.”

The issue arrives back at the high court in an unusual posture.

Neither side has briefed the justices on the constitutionality of the executive order. Instead, the primary dispute is over the scope of injunctions issued by individual district court judges.

“It focuses only on whether it is appropriate for courts to issue nationwide injunctions against the President’s egregiously unconstitutional executive order, as opposed to remedies limited to people directly involved in the litigation or those living in states that have sued the government,” said Ilya Somin, a constitutional scholar at the Cato Institute.

The Trump administration has complained that judges should only be allowed to block a contested policy insofar as it impacts the actual plaintiffs who brought the case — not block it universally.

“Only this Court’s intervention can prevent universal injunctions from becoming universally acceptable,” acting solicitor general Sarah Harris wrote in the government’s application to the court.

Many of the administration’s high-profile attempts to reshape the federal government, sharply curtail federal spending, transform immigration policy, and limit protections for LGBTQ people have been blocked by nationwide injunctions issued by district courts.

Justice Department attorneys from administrations of both political parties have long complained about the overuse of nationwide injunctions and alleged incursion on executive branch power. The court may use this case to articulate parameters for when such sweeping injunctions are warranted and when they are not.

“This Court should declare that enough is enough before district courts’ burgeoning reliance on universal injunctions becomes further entrenched,” Harris said, calling on the justices to narrow the injunctions applied to the birthright citizenship order.

Immigrant advocates, civil rights organizations, and Democratic state attorneys general have warned that blocking Trump’s birthright citizenship in some places but not others — or, exempting a small group of plaintiffs but not others — would create chaos.

“A situation where Trump’s order is in force for some people, but not others (or, alternatively, in some states but not others), creates obvious confusion and anomalies,” he said, “especially when it comes to a policy (citizenship rules) that is supposed to be uniform throughout the nation.”

Some legal scholars say it may be impossible for the court to address the question of nationwide injunctions without also resolving the underlying dispute over Trump’s attempt to redefine birthright citizenship.

“They’re going to have to address the whole thing,” said Josh Blackman, a constitutional law scholar and professor at South Texas College of Law. “The only way to avoid the scope of the injunction question is to rule on the merits. I believe they’re going to rule against Trump. He gets maybe one or two votes but not much more than that.”

A decision in the case is expected by early summer.