The Trump administration on Monday repeatedly stonewalled a federal judge seeking answers about whether the government had violated his order barring the deportation of more than 200 noncitizens without due process, escalating a conflict that threatened to become a constitutional crisis. At a hearing in Federal District Court in Washington, a Justice Department lawyer refused to answer any detailed questions about the deportation flights to El Salvador that took place over the weekend, arguing that President Trump had broad authority to remove the immigrants from the United States under an obscure wartime law known as the Alien Enemies Act. The...