"In blocking the guard deployment to Chicago, the Supreme Court suggested that a president’s power to federalize the guard — which federal law allows when he can no longer execute the laws of the United States with “regular forces” — would not apply to protecting agents enforcing immigration laws. While the ruling was a blow to his administration’s efforts to crack down on illegal immigration, it appeared likely Trump could still invoke the Insurrection Act to deploy regular forces to Chicago and other cities. Invoking the 19th century law — a controversial move that Trump and his aides repeatedly teased during the 2024 campaign and early in the second term — would give him broad authority to evade restrictions on using the military domestically. A separate National Guard deployment that Trump authorized in New Orleans began Tuesday as part of a heavy security presence for New Year’s celebrations a year after an attack on revelers on Bourbon Street killed 14 people. And Trump gave no indication he is pulling back from using the National Guard in Washington, DC, where it is operating under a different federal law that was not at issue before the Supreme Court."