The Trump administration’s immigration crackdown is expanding, but the public data that tracks it is drying up. Researchers and advocates say they can't hold the administration to account for one of its most contentious policies. The Department of Homeland Security has stopped or slowed updates on major dashboards and monthly reports. Those tools used to show arrests, detentions, removals and nationalities. The numbers that are available have come from lawsuits or are mandated by Congress. Researchers are having to piece together the immigration landscape based on what they say are incomplete and unverifiable figures from the Republican administration.