Read the opinion
TRUMP v. UNITED STATES
CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE DISTRICT OF COLUMBIA CIRCUIT
No. 23–939. Argued April 25, 2024—Decided July 1, 2024
Just like the president can send the military after Osama bin Laden, who was never adjudicated for any crime, lock up "enemy combatants", indefinitely, even after the war is over.
Then with a presidential determination, declare anybody to be an enemy of the country.
Ex: President Bush signed Executive Order 13224 on September 23, 2001
Trump could very well send seal team six after political rivals.