AMNA NAWAZ: In a northeastern corner of Montana sits the small town of Froid.

Rural and deeply conservative, it backed President Trump during every one of his White House runs.

But, earlier this year, when federal immigration agents detained one of the town's longtime residents, this tight-knit community pushed back.

Here's Montana PBS' Matt Standal.

MATT STANDAL: Just 50 miles from the Canadian border, the town of Froid is home to less than 200 people.

For more than a decade, Roberto Orozco-Ramirez has been one of them.

MARVIN QUALLEY, Resident of Froid, Montana: Roberto's our neighbor.

He's a part of our community.

MATT STANDAL: Over the years, Roberto has come to mean a lot of things to a lot of people here.

He's a local diesel mechanic, little league coach, and father of four boys.

SHERI CRAIN, Mayor of Froid, Montana: Great businessman.

He's my neighbor, been my neighbor next door for 11 years.

MATT STANDAL: But what residents of Froid didn't know until recently is that Roberto is also an undocumented immigrant who had been deported back in 2009.

KEITH NORDLUND, Resident of Froid, Montana: Up until six months ago, I didn't know Roberto was illegal.

MATT STANDAL: Neighbor Keith Nordlund says Border Patrol vehicles started showing up around town in early January.

KEITH NORDLUND: We had -- 24 hours a day, seven days a week, we had at least two Border Patrolmen in our town.

MATT STANDAL: Agents staked out Roberto's house and, according to his neighbors, even harassed Roberto's children.

KEITH NORDLUND: I personally don't believe that's right.

Them four boys are American citizens.

MATT STANDAL: Roberto turned himself in on January 25.

The government charged him with illegal reentry and immediately took him into detention, telling Montana PBS that this enforcement action represents a community safety priority.

KEITH NORDLUND: The beef is donated by local ranchers.

MATT STANDAL: Within days, Keith Nordlund found himself organizing the biggest fund-raiser this town had ever seen to help Roberto.

More people showed up to the Froid Community Center than the town has residents.

They shared a meal.

They bid on hay and gravel and tools, raising thousands of dollars for Roberto's family.

A separate legal fund raised thousands more.

ROBERTO OROZCO-LOZCANO JR., Son of Roberto Orozco-Ramirez: It's really hard seeing that now he's in jail.

MATT STANDAL: Roberto Orozco Jr.

is Roberto's oldest son.

He says his father fled cartel violence in Mexico as a teenager and came here to build a better life.

ROBERTO OROZCO-LOZCANO JR.

: It's incredible seeing such a hardworking man, I mean, my dad.

being in a situation like this.

I just don't find it very fair.

MATT STANDAL: When Montana attorney Laura Christoffersen heard about Roberto, she says she began studying immigration law and hired an expert thanks to those private donations.

And what they found changed everything.

LAURA CHRISTOFFERSEN, Attorney: What we believe is that, even in 2009, at the time of his first deportation, he was not afforded due process, which means he was illegally removed.

MATT STANDAL: Christoffersen says she found mistake after mistake in the way federal authorities handled Roberto's deportation and says, since January, ICE agents have repeatedly violated his rights.

LAURA CHRISTOFFERSEN: I think people should understand that this is the person who's been in the U.S.

more than 25 years, raised a family with four U.S.

citizen children who are contributing members of our community.

They pay taxes.

They obey the rules.

They follow the law.

They don't take from our society.

MATT STANDAL: In this deep red part of the state, there are mixed feelings about Roberto's legal status.

But Keith Nordlund says this ordeal has caused him to question some long-held political beliefs.

KEITH NORDLUND: I'm not OK that Roberto was here illegally.

I don't believe that's right.

However, our system is so broken that a guy like Roberto that's came here, has worked his butt off, has built a business, he's thriving in a niche, and he is a valuable asset to our community, how is there not a way for him to be legal?

WOMAN: Orozco-Ramirez v. Visser et al.

MATT STANDAL: Last month, Roberto's legal team made their case in a Montana courtroom, arguing the Trump administration denied Roberto his constitutional right to due process.

Roberto's neighbors drove six hours across the state to attend the hearing.

MAN: There's probably 25 from the Froid community.

MAN: I think it's kind of crazy to me how much this has affected the community.

WOMAN: He is so important to us as a community.

MAN: Because this isn't just about the letter of the law.

This is about humans.

WOMAN: Good neighbors, the kind that you want.

MATT STANDAL: Roberto's four children sat in the front row while lawyers argued for and against his release.

The federal judge ultimately sided with Roberto and against the Trump administration.

So, after more than 100 days behind bars, Roberto was released from jail.

And as he walked out of the Cascade County Detention Center, his oldest son was there to surprise him.

And when he finally made it back to Froid, Roberto's neighbors lined the streets, cheering him on as he made his way back to home.

(CHEERING) MATT STANDAL: Roberto says this tight-knit community is what got him through ICE detention and helped him to keep one important thing in mind the whole time.

ROBERTO OROZCO-RAMIREZ, Former Detainee: Well, I think knowing that I wasn't alone or my family wasn't alone, you just could be pushing, and I have been going through whatever just to get to this day.

MATT STANDAL: The residents of Froid never expected the nationwide crackdown on immigration to make its way to their tiny town, but, when it did, they were determined to stand up for one of their own.

(HORNS HONKING) MATT STANDAL: For the "PBS News Hour," I'm Matt Standal in Froid, Montana.