In a significant legal development, the Supreme Court has decided to examine the constitutionality of an executive order issued by President Donald Trump concerning birthright citizenship. This controversial order asserts that children born in the United States to parents who are either residing illegally or temporarily in the country should not automatically gain U.S. citizenship.

The nation’s highest court will review President Trump’s appeal against a lower court’s decision that invalidated these citizenship restrictions. As it stands, the order has not been implemented anywhere across the United States.

Arguments for this case are slated to take place in the spring, with the court expected to deliver a definitive ruling by early summer.

Signed on January 20, the commencement day of Trump’s second term, the birthright citizenship order is a cornerstone of his administration’s aggressive immigration policy. This broader strategy also includes heightened immigration enforcement in various cities and the unprecedented peacetime activation of the 18th-century Alien Enemies Act.

In the face of numerous legal challenges, the administration has encountered mixed outcomes in emergency orders issued by the courts. For instance, the Supreme Court halted the use of the Alien Enemies Act for the expedited deportation of Venezuelan nationals accused of gang affiliations without legal proceedings. However, the justices permitted the continuation of extensive immigration stops in the Los Angeles area after a lower court had previously blocked such practices due to concerns of racial and demographic profiling.

The Supreme Court is also considering an emergency appeal from the administration, seeking permission to deploy National Guard troops for immigration enforcement in Chicago. This deployment has been indefinitely suspended by a lower court ruling.

Birthright citizenship is the first Trump immigration-related policy to reach the court for a final ruling. His order would upend more than 125 years of understanding that the Constitution’s 14th Amendment confers citizenship on everyone born on American soil, with narrow exceptions for the children of foreign diplomats and those born to a foreign occupying force.

In a series of decisions, lower courts have struck down the executive order as unconstitutional, or likely so, even after a Supreme Court ruling in late June that limited judges’ use of nationwide injunctions.

The Supreme Court, however, did not rule out other court orders that could have nationwide effects, including in class-action lawsuits and those brought by states. The justices did not decide at that time whether the underlying citizenship order was constitutional.

Every lower court that has looked at the issue has concluded that Trump’s order violates or likely violates the 14th Amendment, which was intended to ensure that Black people, including former slaves, had citizenship. Birthright citizenship automatically makes anyone born in the United States an American citizen, including children born to mothers who are in the country illegally, under long-standing rules.

The case under review comes from New Hampshire. A federal judge in July blocked the citizenship order in a class-action lawsuit including all children who would be affected.

The administration had also asked the justices to review a ruling by the 9th U.S. Circuit Court of Appeals in San Francisco. That court, also in July, ruled that a group of Democratic-led states that sued over Trump’s order needed a nationwide injunction to prevent the problems that would be caused by birthright citizenship being in effect in some states and not others. The justices took no action in the 9th circuit case.

The administration has asserted that children of noncitizens are not “subject to the jurisdiction” of the United States and therefore not entitled to citizenship.

“The Fourteenth Amendment’s Citizenship Clause was adopted to grant citizenship to newly freed slaves and their children-not…to the children of aliens illegally or temporarily in the United States,” top administration top Supreme Court lawyer, D. John Sauer, wrote in urging the high court’s review.

Twenty-four Republican-led states and 27 Republican lawmakers, including Sens. Ted Cruz of Texas and Lindsey Graham of South Carolina, are backing the administration