Trump Could Send Troops Into U.S. Cities Under Insurrection Act, Supreme Court Justice Kavanaugh Signals

Court denies Guard federalization

On the last day before its Christmas recess, the U.S. Supreme Court denied an emergency request from the Trump administration to federalize Illinois National Guard troops that were slated to support federal immigration enforcement near Chicago.

The court's decision left intact a lower-court injunction that barred deploying those Guard troops on city streets.

The unsigned brief order said the government had not shown legal authority under Title 10 or any inherent presidential power to federalize the Guard "at least in this posture."

That result left in place U.S. District Judge April Perry’s order blocking the deployment while litigation continues.

The denial was widely described as a 6–3 outcome, with Justices Alito, Thomas and Gorsuch dissenting.

This account reflects the court action, the immediate legal posture, and the continuing litigation.

Ruling on military authority

Justice Brett Kavanaugh wrote a separate concurrence emphasizing narrower grounds: he agreed the specific Chicago deployment should be blocked but signaled that the Court's order did not resolve the president's broader authority under the Insurrection Act or Article II to use active-duty military to protect federal personnel and property.

Kavanaugh's concurrence, cited in multiple outlets, suggested future invocation of the Insurrection Act could be legally distinct from the Guard-federalization question decided in this emergency order, a point that generated attention because the Insurrection Act is long-standing statutory authority an administration might consider.

The Court's majority, however, stressed statutory limits and interpreted the phrase "regular forces" to likely refer to the regular U.S. military, meaning the President must identify statutory or constitutional authority to "execute the laws" with the military and show inability to do so with regular forces before using the Guard in this way at the preliminary stage.

Insurrection Act limits

Legal experts and commentators emphasized the political and practical limits on invoking the Insurrection Act.

CNN quoted scholars warning that using the statute would be politically fraught and could create stark martial optics if regular troops such as the 82nd Airborne were sent into U.S. cities.

Elizabeth Goitein told CNN that the Court’s treatment of the statute could constrain future reliance on the Insurrection Act.

Newsweek and other outlets explained that the Insurrection Act of 1807 grants the president authority to call up military forces to suppress rebellion or domestic violence.

Justice Kavanaugh’s concurrence explicitly left open that statutory route, prompting discussion that the Act’s broad language could be invoked despite political risks.

Several outlets also noted that this Court action may make future invocations legally and politically contested.

Reactions to court ruling

Dissenting justices and political figures framed the outcome differently.

Justices Alito, Thomas and Gorsuch publicly dissented, and some critics said the majority raised new arguments on limited briefing; Justice Gorsuch urged narrower, record-based decisionmaking, according to SCOTUSblog.

On the political front, Illinois officials and Chicago leaders who sued to stop the deployment hailed the rulings as a defense of state sovereignty and public safety, with Gov. J.B. Pritzker calling the ruling a "big win for Illinois and American democracy" and local leaders noting Judge Perry's finding that protests did not amount to an insurrection.

The split among the justices underscores legal and political fault lines over using federalized Guard or active military forces domestically.

Federal troops legal patchwork

The decision leaves open unresolved questions and broader context, including related litigation (such as a Portland case) and the 7th Circuit’s treatment, which together form a patchwork of rulings about federal troops, federalization of the Guard, and municipal authority.

Several outlets note the government had earlier federalized Illinois and Texas Guard members and sought deployments in other cities, and courts have handled those moves unevenly.

The 7th Circuit and lower courts found no rebellion and limited federal authority in these circumstances, while another appeals court allowed some troops to remain in Washington, D.C., given its federal status.

Observers therefore say the immediate order blocks the Chicago deployment but does not settle whether the Insurrection Act could be invoked in other settings or the precise boundaries of 'regular forces' and presidential power outside this emergency posture.