The U.S. Supreme Court will hear arguments Thursday in a case that could have major implications for the future of executive authority and the use of nationwide injunctions by federal district courts.

The consolidated case, Trump v. CASA, centers on President Donald Trump’s executive order ending birthright citizenship for children born in the United States to illegal immigrants—a policy blocked by multiple lower courts.

Three federal district judges issued nationwide injunctions that prevented the Trump administration from implementing the order, despite the executive branch’s longstanding constitutional authority over immigration matters.

The high court is now being asked to consider whether such sweeping judicial actions overstep the proper role of the courts.