President Donald Trump got a rare and devastating blow at the Supreme Court on Tuesday, as three right-wing justices joined with the three liberals to deny a stay of a lower court ruling that prevents him from federalizing the National Guard to deploy troops to Chicago — and said the administration is unlikely to prevail when the case is litigated on the merits.....

"The Supreme Court just agreed: President Trump violated the law by deploying the National Guard in Illinois," wrote New Jersey Attorney General Matt Platkin. "Proud to stand with @ILAttyGeneral [and] my colleagues in successfully opposing this unnecessary and unlawful deployment."

Yet another key analysis came from American Immigration Council senior fellow Aaron Reichlin-Melnick, a lawyer who has frequently criticized the Trump administration's immigration policy.

"Wow. Genuinely shocked, and a hugely consequential decision. This is a case where [law professor] Marty Lederman's amicus brief appears to have made a MAJOR impact. Before he wrote it, courts were sidestepping the 'regular forces' issue entirely. And that's what the Trump admin lost on," wrote Reichlin-Melnick. "The law Trump used to federalize the National Guard requires him to be 'unable with the regular forces to execute the laws of the United States.' The Court today agrees with Professor Lederman that 'regular forces' means the U.S. military, which used to be called 'the regulars.'"

"There are other laws which permit the President to call up the National Guard, the most famous of which is the Insurrection Act. But Trump has not invoked that law. Instead, he invoked a law which had strict prerequisites, which the Supreme Court ruled were not met," wrote Reichlin-Melnick. Additionally, "the majority finds at this stage that the President does not have inherent authority to deploy the military to protect ICE property, therefore allowing him to 'execute' the laws with the military. The majority says no."