President Donald Trump issued an executive order Thursday, saying sanctuary cities “have caused immeasurable harm to the American people and to the very fabric of our Republic.”

But what is a sanctuary city? The Nevada Independent asked Michael Kagan, director of the Immigration Clinic at UNLV's Boyd School of Law, and Alyson Sincavage, legislative associate at the American Immigration Lawyer Association.

Q: Does the term “sanctuary cities” mean anything?

A: The term is mostly symbolic and can mean different things to different people, but it’s tied to policies that have real meaning. Municipalities can make a range of moves that could be considered “sanctuary” provisions, from symbolic resolutions and ordinances to prohibitions on holding someone in jail for longer than their original sentence to give Immigration and Customs Enforcement (ICE) time to question them.

Q: The Las Vegas Metropolitan Police Department said in July 2014 that it will not cooperate with all ICE requests for detentions. Why would a police agency do that?

A: The agency feared it could be violating the 4th Amendment (unreasonable search and seizure) if it cooperated with ICE. Shortly before Metro announced its new policy, a federal judge ruled that Clackamas County, Oregon violated the Constitution by holding a woman in jail for 19 hours after her case was settled so ICE agents could investigate her residency status.

Then-Clark County Sheriff Doug Gillespie said he wanted to wait until courts offered more clarity on the matter.

“This change has nothing to do with me taking a stand on the immigration issue,” he said at the time. “It has more to do with a situation we’ve found ourselves in and this is the best thing to do until the feds figure it out.”

Q: How might ICE policies violate the 4th Amendment?

A: ICE’s requests for law enforcement to hold people are typically signed by an ICE agent but not an independent judge who verifies that there’s probable cause for the hold, according to Professor Michael Kagan of the Immigration Clinic at UNLV's Boyd School of Law.

By contrast, a police officer seeking a search warrant would need to make his or her case before a judge before getting it.

While the ICE detainer process has long been standard practice, Kagan said it’s now a “legacy policy” and “federal courts are really rethinking due process in the immigration context.”

He said overloaded immigration courts would have trouble signing off on all requests for holds, but the agency needs to fix its processes.

“ICE has a problem that it hasn’t wrestled with,” Kagan said.

ICE officials didn’t immediately return requests for comment on Thursday.

Q: Who is most affected by ICE detainers?

A: While suspects in homicide cases are unlikely to get bail in the first place, the detainers can have a disproportionate impact on people being held for lower-level crimes such as DUI or battery. Some police agencies will hold an arrestee and won’t grant bail if ICE has requested a detainer on that person, Kagan said.

“Someone that would normally be out quickly would be there for weeks and months,” he said. “They spend the time in jail on the county dime.”