David Morales teaches social studies at Mayfield High School, in Las Cruces, New Mexico, a city of a hundred thousand people, located fifty miles north of the Mexican border. Some of his students are the children of undocumented immigrants, and a few of them might even be undocumented themselves. He doesn’t know which ones, exactly, and he doesn’t care. “When they’re in my classroom, I’m there to teach them,” he told me recently. “I make a point of not knowing, unless the student wants me to.” His classes are small, with around twenty students each, and when any kid is out, “it’s obvious,” he said. “But last month it was painfully obvious.”

On February 15th, Immigration and Customs Enforcement (ICE) officers conducted a raid in Las Cruces, arresting people at a trailer park on the outskirts of town. The raid came a few weeks after President Trump signed two executive orders, signalling his plans to fulfill a campaign promise of cracking down on undocumented immigrants. Rumors spread that there were further raids planned, though none took place. On February 16th, a Thursday, Las Cruces’s public schools saw a sixty-per-cent spike in absences compared to the previous week—twenty-one hundred of the district’s twenty-five thousand students missed school. Two thousand students stayed away again the next day. Attendance returned to normal the following week, which made the two-day rash of absences all the more pronounced. “It was alarming,” Greg Ewing, the district’s superintendent, told me. News of the raid caused such fear in the community that Ewing wrote a letter to parents on the 16th, in English and Spanish, reassuring them that “we do not anticipate any ICE activity occurring on school campuses.”

His reassurances only went so far. Students might not have been at risk, but their parents seemed to fear that they themselves would be stopped coming or going from the schools. “Parents often don’t have legal papers,” he said. “They just have to survive day by day so their kids can get educated.” At the city’s high schools, absences went up by twenty-five per cent in the two days after the raids, but the numbers were even higher at the schools for younger students, where many still rely on their parents to drop them off and pick them up every day. In the two days after the raids, absences at elementary schools rose by almost a hundred and fifty per cent.

“As my students filed in, I was worried,” Morales said. “Who’s not going to be here?” In one of his classes, three students were missing on the 16th. The next day it was five. “My first thought was, Are they O.K.?” he said. “Then, What if their parents got picked up? Do they have a place to stay?”

Jennifer Amis, the principal of Arrowhead Park Early College High School, where the student body is almost entirely Hispanic, received a call from the nurse’s office on the morning of the 16th. A freshman had been there, sobbing, since her mother dropped her off that morning. They had been in the car, en route to school, when they spotted roadblocks set up by immigration officers checking for citizenship papers along the highway; they doubled back, taking back roads to get to school. The mother had decided to stay home from her job at a restaurant, but the girl’s father had gone to work earlier that morning. “She and her mother called him as soon as they arrived at school,” Amis said. “They said they hoped to see him that night.” The student was rattled, but she came to school both that day and the next. “There were other students we just stopped seeing,” Amis said. One morning the next week, several parents, still concerned, came in after requesting to meet with her. “The families were afraid to express anything factual about themselves,” she said. “They are reluctant to tell us what’s going on. We have to do most of the talking. We have to reassure them that their kids are safe.”

Fears about immigration raids extend well beyond the borderlands, and community-wide reactions like the ones in Las Cruces were seen during the Obama Administration, too. A former Department of Homeland Security official under Obama, who asked that his name not be used, told me that the department used to receive anguished letters not just from educators who witnessed spikes in student absences after immigration raids but also from doctors whose patients missed appointments because they were scared they'd be targeted by ICE agents at hospitals. In the winter of 2016, community concerns regarding possible raids prompted the C.E.O. of Prince George’s County public schools, in Maryland, to write a letter to D.H.S., lamenting the “devastating impacts . . . on the academic, social and emotional well-being of all of our students.” A month later, attendance at a high school in Durham, North Carolina, dropped precipitously after a student was taken into custody by immigration agents while walking to school. Last month, a few school districts around the country noted that a large number of student absences coincided with “Day Without Immigrants,” a nationwide work boycott, on February 16th, organized in response to the Administration’s anti-immigrant policies. But in Las Cruces school officials had no doubts that it was the raid that caused attendance to drop.

“There's always some recoiling after raids or policy announcements,” Roberto Gonzales, a professor of education at Harvard and the author of “Lives in Limbo,” told me. “But in the last month or so there have been conflicting messages from the Trump Administration regarding its enforcement policy. There have been several large-scale and visible enforcement actions. Parents have been picked up after dropping off their children from school. All of this fuels rumor and dread for worst-case scenarios.”

In Las Cruces, the district’s social workers have been making house calls to visit families whose children were absent from school after reports of the raid. One day late last month, a social worker named Julie Kirkes drove to a dilapidated, flat-roofed stucco house in town. A small window on the front side of the house was covered by a sheet. It was the address she’d been given for the family of an elementary-school student with a good attendance record who hadn’t shown up for several days after the raid.

When Kirkes knocked on the door, a middle-age woman answered, and led her inside. “The inside of the house was almost cave-like,” Kirkes said. As they walked into a small, dark living room, she noticed a large blanket hanging from the ceiling of the hallway, blocking her view. “The families don’t know me personally, and when they hear ‘social worker’ they get scared and often think that it’s the person who takes their kids away,” Kirkes said. She asked the woman whether the child needed health care, clothes, or food. After a few minutes, the woman seemed to relax. She called out to the rest of the family, who’d been hiding in the hallway, behind the blanket. “You can come out now,” she shouted, and three children, their father, and grandfather appeared. A few days later, the child returned to school. During the last month, Kirkes has visited a few other houses that had been abandoned before she arrived—the residents had fled.

In 2011, D.H.S. issued a policy memo to field officers outlining a list of so-called “sensitive locations”—including schools, churches, and hospitals—where they should refrain from searching, interrogating, or arresting individuals “for the purpose of immigration enforcement.” D.H.S. insists that its agents still follow the policy, but immigrant-community advocates are concerned that a new culture is taking root among the agency’s rank and file. “The Administration has embraced the notion that it has removed the handcuffs from ICE and C.B.P. personnel, which is likely to lead many to believe they can ignore written policies with impunity,” Tom Jawetz, the vice-president of immigration policy at the Center for American Progress, told me.

The principle of “sensitive locations” has always been ambiguous, which only compounds the current fears in Las Cruces. “Where does the safe zone end? At the bus stop? On the school bus?” Maria Flores, the president of the city’s board of education, said. Ewing, the superintendent, shared with me a note he had distributed to the city’s school-bus drivers, to carry with them while transporting students on field trips. Because Las Cruces is so close to Mexico, Border Patrol checkpoints are common along the highways leading in and out of town. Forty students from various district high schools recently attended a language expo at the University of New Mexico, in Albuquerque, which meant passing through these checkpoints. “I authorize that the students, staff, and chaperones on this bus travel together for an educational activity,” Ewing wrote. So far, at least, the power of his note to prevent federal agents from conducting immigration enforcement has not been tested.

Last week, I spoke by phone to an undocumented woman whose two daughters, aged ten and thirteen, are enrolled in elementary and middle school in Las Cruces. She asked me not use any of their names, and would only speak to me in the presence of her younger daughter’s school principal, whom she trusted. Each morning, she drives her two daughters to school, dropping them off, one after the other, before heading to her job as a home-aid worker. “School goes hand in hand with the home,” she said. “I speak to my daughters’ teachers all the time to make sure everything is going well. They are going to attend college someday.” The decision to keep her daughters home from school wasn’t something she took lightly. But for four days after the raids, the three of them stayed inside their house. “They wanted to leave, but I told them we couldn’t—not yet,” she said.