Most readers are likely aware of the basic facts of the case of Kilmar Armando Abrego Garcia, the El Salvadoran man who was legally living in Maryland pursuant to a 2019 court order forbidding the government from deporting him to his home country, where, the court found, he would face persecution. The Trump administration has admitted that sending Abrego Garcia to a supermax prison in El Salvador known for human rights abuses was an “administrative error” but contends before the U.S. Supreme Court that there is nothing a federal court can do about that. As I shall explain, the Solicitor General’s argument ultimately rests on the claim that the president who frequently boasts about his abilities as a deal maker is a lousy negotiator.