Currently, ICE's 287(g) program allows for state and local law enforcement to collaborate with ICE in its efforts "to protect the homeland through the arrest and removal of noncitizens." However, this does not include sheriffs themselves rounding up and detaining undocumented immigrants.

Additionally, no federal funding has been appropriated to any sheriffs' offices that help ICE, meaning just 125 out of 3,081 sheriff's offices in the U.S. have signed up. And Yuma County, Arizona Sheriff Leon Wilmot told WIRED that the Supreme Court has already established that enforcing immigration law is outside the jurisdiction of local police departments and sheriffs' offices.

"[T]hat's not our realm of responsibility," Wilmot said. "If we wanted to do immigration law, we would go work for Border Patrol."

The push for sheriffs to assist the incoming administration has been led by retired sheriff Tom Mack, who is the head of the Constitutional Sheriffs and Peace Officers Association (CSPOA). Mack told WIRED he's been exchanging voice and text messages with Homan about getting more sheriffs involved with deportations. Homan has previously promised to build "the biggest deportation force this country has ever seen." But Wilmot said "no one listens to" Mack, that he "hasn't been a sheriff in a long time" and that he "pushes his own agenda."

Santa Cruz County Sheriff David Hathaway, who is a Democrat, told WIRED that he wasn't invited to an event Homan hosted in his state last month, even though Hathaway's jurisdiction includes some of the nation's biggest ports of entry. He added that he would refuse any calls to help the Trump administration deport immigrants, as it would hurt his standing in his county.

"I'm not going to cooperate, because 95 percent of the residents of the town where I live, where my county is, are Hispanic,” Hathaway said. “I'm not going to go checking the documents of practically every single person in my county to determine their immigration status, because that would create distrust between law enforcement and all the people in my community."

The sheriffs bucking calls to assist with mass deportations even include some of Trump's biggest supporters in the law enforcement community. Livingston County, Michigan Sheriff Mike Murphy — who hosted a pro-Trump rally in a building owned by the sheriff's office — told the outlet that he isn't interested in using county resources to help with federal immigration law enforcement.

"I still have a county to do police work in,” Murphy said. “Just because the president says, 'Hey, go out and round them up,' that is not all of a sudden gonna move to the top of my priority list. If somebody's house is getting broken into, that's my priority. If somebody's involved in an injury crash and they're laying on the side of the road, that's my priority. I've got cases that are open.”

Other border state sheriffs who have come out against calls to help the Trump administration round up migrants include Val Verde County, Texas Sheriff Joe Frank Martinez and Brewster County, Texas Sheriff Ronny Dodson. According to Dodson, the incoming Trump administration giving sheriffs the authority to jail migrants could "break" county law enforcement.

"I’m not gonna let the government tell me what to do in my job," Dodson said.