PIERSON, Fla. — When a trio of squad cars pulls up to the fern field, the workers — bent over, piling up bundles of freshly cut feather-like fronds in the late-morning sun — grow tense.

Sgt. Roy Galarza, 34, and his brothers, both sheriff's deputies, jump out. Roy jokes in Spanish about who will cut the most ferns that day, and greets an uncle who works there. Slowly, the workers, many of whom are undocumented immigrants from Mexico, walk over to the cruisers and begin to chat: One woman complains about a traffic stop; another talks about a friend’s misunderstanding with police involving her children.

The Galarza brothers — Roy, Daniel, 36, and Billy, 26 — aren't there to arrest anyone. They're visiting the fields as part of the Volusia County Sheriff Department's redoubled efforts to build trust in an immigrant community that fears the police and the deportations President Donald Trump has promised.

The Galarza brothers, Daniel, Roy and Billy, stand in a farm on April 12, 2018 in Volusia County. Gerardo Mora / ipaphoto.com for NBC News

Trump has repeatedly demonized so-called sanctuary cities as hotbeds of crime where illegal activity permitted by politicians runs rampant. He tweeted on Monday that such policies are "inspired" by Democrats.

Despite the Democrat inspired laws on Sanctuary Cities and the Border being so bad and one sided, I have instructed the Secretary of Homeland Security not to let these large Caravans of people into our Country. It is a disgrace. We are the only Country in the World so naive! WALL — Donald J. Trump (@realDonaldTrump) April 23, 2018

Meanwhile, his Justice Department has threatened to pull federal funding from major urban areas that it has claimed are in violation of federal laws, and, last month, announced a lawsuit against the state of California over its policies that aim to protect immigrants from deportation.

But there's another, less publicized part of the sanctuary movement — largely rural counties, like Volusia County in Florida, which favored Trump in 2016 by 13 points, but whose law enforcement officials say they need to protect immigrants working in the community and are pushing back on federal, state and local efforts to shut them down.

Volusia County is home to NASCAR's Daytona 500 and Daytona Beach; with around a half million residents and 1,101 square miles, the county sits on the state's eastern coast about an hour's drive north of Orlando. Its largest city is Deltona, with an estimated 90,000 residents, but it also includes the tiny town of Pierson, which calls itself the fern capital of the world.

"As soon as Trump took over, that was the biggest concern — people being deported," Roy told NBC News. "That's going to affect the relationship with the Hispanic community and the sheriff's office, (when people worry), 'Now if I get pulled over, what’s going to happen?'"

Roy worries that domestic violence frequently goes unreported in Pierson, and knows that muggings do because criminals target undocumented immigrants. "They know they're not going to report it,” he said.

Indeed, workers interviewed through a translator said they all feared law enforcement, but felt they could cautiously trust the Galarza brothers.

Voting for Trump, but protecting its own

In 2016, Volusia County elected both Trump and a sheriff bent on restoring trust within the immigrant community.

"Where does crime come from? Crime comes from when you marginalize a race or a religion and you knock them out of mainstream society," said Sheriff Michael Chitwood, a political independent who was sworn in the same month as the president. "When I first got elected, I went to every church and asked the pastors to trust me and said there's a different way we're going to do things."

Chitwood said he instituted a new anti-profiling policy and began doing regular outreach at churches and schools, trying to convince the community that working with the police won't end with a deportation.

At one church visit, the sheriff told NBC News, four or five people came up to him to tell them that one deputy was constantly pulling them over. They showed Chitwood photos of the man on their cellphones. After Chitwood checked the department's records, he found that the deputy was routinely going 10 miles out of his assigned zone to do traffic stops in immigrant neighborhoods.

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Chitwood opened an investigation the next day, and the officer retired. The sheriff wrote a new policy that said police need significant probable cause, like a visible tattoo signaling membership in a gang or cartel, to ask about citizenship at a traffic stop.

There is no clear definition of what makes a city a "sanctuary" for undocumented immigrants, and the majority are actually counties, according to groups that track it. The Justice Department declined to offer an official definition of the term.

Instead, DOJ pointed to letters it sent municipalities that said refusing to inquire about immigration status and failure to honor ICE detainer requests — when the federal government asks municipalities to hold someone in prison for 48 hours plus weekends and holidays, so that Immigration and Customs Enforcement can come and get them — were a violation of federal law.

Even though Volusia stopped honoring detainer requests in 2014, Chitwood is quick to argue that his county is not a sanctuary — his department communicates with ICE, it just doesn't do their work for them, he said, noting that the county receives few ICE detainer requests.