Judge Aaron Bress authored the opinion in the 2-1 decision for the 9th U.S. The court said the Trump administration misinterpreted a 1996 law it used to justify detaining migrants without bond hearings. The ruling could potentially affect millions of migrants living in the U.S. who are seeking to remain in the country after living there for decades without legal status. The policy treated undocumented immigrants already in the country the same as newly arriving migrants at the border. It is the fifth federal appeals court to rule against the Trump administration on the issue, while two appeals courts have sided with the White House.