The Justice Department petitioned the Supreme Court on Friday to preserve the key program that solved last year’s border surge, after a lower court ruled it was illegal. Known formally as the Migrant Protection Protocols (MPP), and more commonly called “Remain in Mexico,” the policy allows the U.S. to push migrants who entered from Mexico back across the border to wait for their immigration court dates. About 60,000 migrants had been subjected to MPP. The 9th U.S. Circuit Court of Appeals issued a ruling last week that MPP was illegal, but stayed the order. On Wednesday, the court gave the...