As the Trump administration has stepped up enforcement of immigration laws, mayors and police chiefs across the country have vowed to resist, declaring their communities “sanctuary cities” and in some cases filing lawsuits to try to block federal efforts that would force local authorities to cooperate with immigration agents. Less noticed, however, has been a wave of mostly smaller communities moving in the opposite direction and voluntarily partnering with federal authorities to enforce immigration laws.

Immigrations and Customs Enforcement last month announced that 18 counties in Texas had signed so-called 287(g) agreements, in which law-enforcement agencies agree to review the immigration status of inmates in their local jails and to turn people suspected of immigration violations over to federal authorities. The 20-year-old program — which former President Barack Obama at one point tried to scale back — has expanded greatly under President Trump. Sixty communities now have active 287(g) agreements, which is nearly twice as many as a year ago, according to ICE; only six communities signed new agreements between 2012 and 2016. The growth is likely to continue: In January, Trump signed an executive order calling for the Department of Homeland Security to negotiate more partnership agreements.

The expansion of the program has raised alarm among some immigrant-rights advocates who worry that it encourages racial profiling and can drive a wedge between immigrant communities and local law-enforcement officers. Some police departments are already observing that Trump’s presidency seems to be having a chilling effect on the number of crimes, such as sexaul assault, reported among Latino populations, though it’s difficult to say how much of that chill might be caused by the president’s rhetoric or policies. (My colleague Rob Arthur looked at these claims earlier this year and found at least some statistical evidence to support the anecdotal observations that Latinos are reporting fewer crimes.)

“What those agreements have historically done have eroded the trust between the local law enforcement and communities they’re intended to protect and serve,” said Edgar Saldivar, a senior staff attorney at the American Civil Liberties Union of Texas.

Supporters of the agreements, however, argue they improve public safety by targeting undocumented immigrants who have committed crimes. “This program acts as an invaluable force multiplier for ICE’s public safety mission, allowing the agency to take custody of criminal aliens,” ICE spokeswoman Sarah Rodriguez said in a statement.

The 287(g) program was established under the Illegal Immigration Reform and Immigrant Responsibility Act of 1996, but the agreements were little used until 2002, under the George W. Bush administration. The program has evolved over time: All current agreements pertain only to people who are already in jail, but under Bush, law-enforcement officers in some communities checked people’s immigration status when they were first stopped by police, before they were convicted and in some cases before they were charged with a crime. In 2009, however, a report from the Government Accountability Office found that communities in which the program was implemented reported widespread concerns that it would lead to racial profiling and intimidation; the agency concluded that “the lack of internal controls governing the program limits ICE’s ability to take full advantage of this additional resource.” Later, DHS conducted two audits of the program, and ICE issued guidelines aimed at strengthening civil rights standards and focusing enforcement efforts on criminals who pose the greatest threat to public safety. In 2012, the Obama administration began scaling back the program in favor of other enforcement efforts including Secure Communities, a similar arrangement that forwards fingerprints taken by local police to DHS, which checks to see if the arrestees are in a federal database.

In the program’s current form, 287(g) agreements apply only in jails: Local officials use a federal database to review inmates’ immigration status and notify ICE of anyone who is undocumented or who may be subject to deportation for other reasons. Eventually, local authorities transfer inmates into federal custody, where they are subject to deportation proceedings. In a memorandum sent this February, however, then-Secretary of Homeland Security John Kelly said ICE should consider broadening the program again in border regions to allow local officials to enforce immigration laws during policing operations outside of a jail setting.

The program is making its biggest comeback in Texas, which is home to 19 of the 60 active partnership agreements. Among the counties signing agreements last month were Tarrant County, home of Fort Worth, Lubbock County in northwest Texas, and several counties outside of Houston. Sheriffs joining the program praised it as a way to move undocumented immigrants convicted of crimes out of their communities. Jackson County Sheriff A.J. “Andy” Louderback said the partnership was about obtaining additional information on arrestees’ criminal backgrounds and immigration status, which his department might not otherwise have access to.

“We have no access to any other federal databases. You have another layer of information and data gathering if you’re a 287(g) partner, and that was important to us as a public safety measure,” said Louderback. “We’re not immigration officers out here in Texas.”

Communities that check inmates’ immigration status Agencies with active 287(g) agreements, which allow law-enforcement officers at local jails to act as ICE agents LAW-ENFORCEMENT AGENCY ▲ ▼

STATE ▲ ▼

SIGNED ▲ ▼

Etowah County Sheriff’s Office AL June ’16 Benton County Sheriff’s Office AR June ’16 Washington County Sheriff’s Office AR June ’16 Arizona Department of Corrections AZ June ’16 Yavapai County Sheriff’s Office AZ June ’16 Pinal County Sheriff’s Office AZ June ’16 City of Mesa Police Department AZ June ’16 Orange County Sheriff’s Office CA June ’16 Collier County Sheriff’s Office FL June ’16 Jacksonville Sheriff’s Office FL June ’16 Clay County Sheriff’s Office FL June ’17 Whitfield County Sheriff’s Office GA June ’16 Hall County Sheriff’s Office GA June ’16 Cobb County Sheriff’s Office GA June ’16 Gwinnett County Sheriff’s Office GA June ’16 East Baton Rouge Parish Sheriff’s Office LA May ’17 Massachusetts Department of Corrections MA June ’16 Bristol County Sheriff’s Office MA Jan. ’17 Plymouth County Sheriff’s Department MA Jan. ’17 Frederick County Sheriff’s Office MD Aug. ’16 Harford County Sheriff’s Office MD Oct. ’16 Anne Arundel County MD June ’17 Wake County Sheriff’s Office NC June ’16 Cabarrus County Sheriff’s Office NC June ’16 Gaston County Sheriff’s Office NC June ’16 Henderson County Sheriff’s Office NC Feb. ’17 Mecklenburg County Sheriff’s Office NC Feb. ’17 Monmouth County Sheriff’s Office NJ June ’16 Hudson County Department of Corrections NJ July ’16 Salem County Sheriff’s Office NJ Dec. ’16 Cape May County Sheriff’s Office NJ April ’17 Las Vegas Metropolitan Police Department NV June ’16 Nye County Sheriff’s Office NV April ’17 Butler County Sheriff’s Office OH Sept. ’16 Tulsa County Sheriff’s Office OK June ’16 Charleston County Sheriff’s Office SC June ’16 York County Sheriff’s Office SC June ’16 Lexington County Sheriff’s Office SC Nov. ’16 Horry County Sheriff’s Office SC June ’17 Knox County Sheriff’s Office TN June ’17 Carrollton Police Department TX June ’16 Lubbock County Sheriff’s Office TX Nov. ’16 Jackson County Sheriff’s Office TX Jan. ’17 Smith County Sheriff’s Office TX April ’17 Waller County Sheriff’s Office TX May ’17 Tarrant County Sheriff’s Office TX June ’17 Goliad County Sheriff’s Office TX June ’17 Calhoun County Sheriff’s Office TX June ’17 Montgomery County Sheriff’s Office TX June ’17 Refugio County Sheriff’s Office TX June ’17 Aransas County Sheriff’s Office TX June ’17 DeWitt County Sheriff’s Office TX June ’17 Galveston County Sheriff’s Office TX June ’17 Lavaca County Sheriff’s Office TX June ’17 Victoria County Sheriff’s Office TX July ’17 Chambers County Sheriff’s Office TX July ’17 Wharton County Sheriff’s Office TX July ’17 Walker County Sheriff’s Office TX July ’17 Matagorda County Sheriff’s Office TX July ’17 Prince William-Manassas Regional Adult Detention Center VA June ’16 Source: U.S. Immigration and Customs Enforcement

Local enforcement of immigration laws has been a hot topic in Texas in recent months. In May, Gov. Greg Abbott signed a bill that would require communities to cooperate with “detainer” requests, in which ICE asks local authorities to keep suspected undocumented immigrants in custody for up to two extra days to give ICE time to pick them up. Police chiefs and local governments from several large cities are fighting the law, which also drew condemnation from national law-enforcement groups such as the Major Cities Chiefs Association. Opponents argue that forcing local law enforcement to participate in immigration activities could undermine public safety by making immigrants reluctant to cooperate with local police.

“Texas has been pretty much ground zero for these kinds of policies and laws,” said Saldivar. “We have heard reports of the tangible fear these immigrant communities have as a result of these operations.”

The 287(g) agreements, however, are voluntary. Proponents of the partnerships say they benefit ICE and local communities by improving immigration enforcement in areas that are underserved by the federal agency or where ICE experiences a heavy workload. The program has at times served as a significant piece of federal enforcement efforts: A study conducted by the Migration Policy Institute in 2011, when the program was near its peak, found that it accounted for about 10 percent of all people identified by DHS as subject to deportation.

“Local officers are doing the work that ICE officers do in other places, and ICE doesn’t have to hire additional personnel to get the coverage it needs,” said Jessica Vaughan, the director of policy studies at the Center for Immigration Studies, an advocacy organization that supports stricter limits on immigration.

Critics, however, have questioned whether the 287(g) program is as targeted as its proponents claim. In its study of the program in 2011, the Migration Policy Institute, a think tank that analyzes migration policies, found that the goals of local programs were often guided by political pressure and enforcement can vary from town to town. While some jurisdictions studied for the report used a targeted approach focusing on criminals who committed serious offenses, other counties issued more than half their detainers in response to traffic violations. In some instances, the report found that detainers were issued before the person in custody was convicted of an offense, which resulted in some people being transferred to ICE custody without going through the court process. “That’s where there’s the greatest danger of racial profiling,” said Randy Capps, director of research for U.S. programs at the institute and one of the authors of the study.

Some sheriffs in Texas have raised a more practical objection: They argue that the benefits of the program aren’t worth the cost. As part of the 287(g) agreement, ICE allots federal funding to pay for officer training and equipment, but local law enforcement agencies are responsible for salaries and other personnel expenses. Earlier this year, Ed Gonzalez, sheriff of Harris County in Texas, announced he was terminating the county’s 287(g) agreement, saying that budgetary and staffing constraints meant that the personnel and the roughly $675,000 the county was paying them in salaries would be better deployed elsewhere. And at a press conference last week, Sheriff Troy Nehls of Fort Bend County, Texas, said he won’t spend the $500,000 it would cost to send staff to train to participate in the program. “It would be irresponsible for me to do that, to throw money at something that isn’t broken,” Nehls said. Louderback, however, said the partnership won’t create additional costs for taxpayers in his county because his department is using personnel already employed by the county jail for the program.

“I would have people in the jail that are cross-trained and have two hats,” said Louderback. “There might additional duties at times, but it’s a public safety concern, so we absorb those costs.”

For some counties, cooperating with federal authorities could be a financial boon. Counties that participate in 287(g) programs also have the option to enter into separate agreements in which the federal government pays them to hold undocumented immigrants in local jails at ICE’s request until immigration officers come to collect them. Sheriff Clint McRae of Walker County, Texas, told The Huntsville Item in April that he wouldn’t participate in the 287(g) program if he couldn’t reach one of these additional agreements with ICE.

“What that does is it helps us generate additional revenue,” McRae told the paper. “It’s more of a business-type of agreement.”

Chris Rickerd, policy counsel at the ACLU’s national political advocacy department said the revenue-generating agreements incentivize bad behavior in police departments. The organization has written several letters urging ICE to end the 287(g) program, citing civil rights violations and misconduct issues in jails, along with anti-immigrant rhetoric from officials in counties applying for the agreements.

“Why anyone would want to voluntarily subsidize Trump’s deportation force and not other public safety costs in their community is a mystery,” said Rickerd.