The administration’s emergency appeal follows rulings by a federal district judge and an appellate panel that temporarily blocked the deployment of roughly 700 Guard troops — 300 from Illinois and 400 from Texas — to the Chicago area.

In a filing to the Court, Solicitor General D. John Sauer urged the justices to intervene, arguing that the president’s order was lawful under federal statutes that permit the use of the Guard when “rebellion” or “obstruction” prevents enforcement of U.S. law. Sauer said the situation around a U.S. Immigration and Customs Enforcement (ICE) facility in Broadview, Ill., meets that standard.

“Violent agitators have repeatedly obstructed access to a critical federal immigration facility,” Sauer wrote. “Local forces have failed to respond, even when federal agents face life-threatening violence.” He said the deployment was necessary to “protect immigration officers and federal buildings” and to relieve federal agents diverted from other assignments to secure the facility.

The dispute centers on Trump’s use of Section 12406 of Title 10 of the U.S. Code, which allows the president to federalize a state’s National Guard when civil authorities are unable or unwilling to enforce federal law. The administration says that provision justifies the move, while Illinois officials argue it amounts to an unconstitutional use of military force within state borders.