In February, U.S. Immigration and Customs Enforcement officers arrest a foreign national during a targeted  operation aimed at immigration fugitives, re-entrants and at-large criminal aliens in Los Angeles.

(Charles Reed/U.S. Immigration and Customs Enforcement via AP)

A Republican sheriff in a conservative part of northern Colorado found himself at odds with the Trump administration recently. Department of Homeland Security officials said Weld County was among dozens of jurisdictions across the country that failed to hold people at the request of federal immigration authorities. The list could become the basis for the Trump administration's plans -- which it reiterated this week -- to withhold grant money from cities and counties that protect undocumented immigrants from federal authorities.

Sheriff Steve Reams says Weld County's inclusion on the list was a mistake, and fought for ICE to remove it from the list. In general, Reams says cooperating with immigration orders is challenging, and sometimes even illegal, like when ICE asks local jails to detain people past their court-ordered release dates so that ICE can evaluate whether they are in the country illegally. 

As the County Sheriffs of Colorado wrote recently, "If federal authorities present us with a warrant or other detainer, signed by a judge or a magistrate, we hold those persons for federal authorities to pick up. However, courts have ruled that we have no authority to hold arrestees on administrative holds that have not been reviewed and approved by federal judges or magistrates."

Reams spoke with Colorado Matters host Nathan Heffel.