Iowa Democrats have struggled to organize Latinos. Julián Castro is trying to change that.

It had taken some work on her son's part to get Villanueva, a 43-year-old native of Texas with Mexican parents, to a quaint local diner because, by her own admission, politics has never interested her. Sitting in Sam's Sodas and Sandwiches, Villanueva was far outside her comfort zone as Julián Castro, the former secretary of Housing and Urban Development and current Democratic 2020 candidate, talked about his campaign and his plans for rural communities like Carroll.

"My son opened my mind and he told me that with everything you do, you also have to vote," Villanueva said after hearing Castro's short stump speech and a question and answer with the 2020 candidate. "I want to be able to learn and teach my friends."

Villanueva exemplifies the kind of unlikely voter Castro, a candidate who often admits he is a longshot to win the Democratic nomination and the presidency in 2020, is trying to organize in Iowa. In a crowded field, Castro and other Democrats know they need to expand the base of Democratic voters to have a shot at winning the nomination, and one way to do that is by engaging people who had previously not participated in the caucus.

But Democratic organizers and operatives throughout Iowa, especially the northwest part of the state where the most concentrated pockets of Latino voters live, say that efforts like these have confounded candidates for decades and are likely to do the same to candidates in 2020.

"It is one of the challenges that we have had as a party," said Troy Price, chair of the Iowa Democrats. "We know that it is a large group of potential voters that have not been engaged as strongly as they could be."

Efforts to organize Latinos in recent years, Democrats said, have been further complicated by President Donald Trump's fiery rhetoric on immigration and increased raids by Immigration and Customs Enforcement across the country.

"If you have family members who are here illegally -- which usually a Latino will know someone who is illegal -- it becomes scary to be involved with anything governmental," said Carlos Valle, Villanueva's 19-year-old son. "It becomes a paranoia, especially with the tension we have right now."

An island in Northwest Iowa

Iowa is not known for its diversity, but the state's Latino population has been growing consistently for the last two decades. Buoyed by employment in the agriculture, meatpacking and construction industries, Latinos now makes up 6% of Iowa's population, making people of Hispanic origin the state's largest ethnic race according to government data.

Iowa Democrats have tried for decades to organize these enclaves of eligible voters to little success.

But Castro's campaign is determined on making organizing these communities central to their strategy in Iowa, something that was apparent throughout his first trip to Iowa as a declared candidate.

"I believe that my candidacy is going to resonate with Americans of all backgrounds, but of course especially with the Latino community that presents an opportunity to bring new people into the fold who haven't been involved," Castro told CNN. "I think what you're going to see is that more and more Latinos are going to come out that haven't before."

Castro's campaign -- from the candidate to his top campaign aides -- believe focusing on organizing Latinos in Iowa could set the former mayor's long shot candidacy apart in what is expected to be an incredibly crowded field. And that strategy informed a host of decisions they made on his trip.

Castro headlined a town hall at Grand View University on the first day of his trip because, as one aide said, it had a more diverse student body than nearby Drake University. The second day of Castro's trip took the candidate to Crawford, Sioux and Woodbury -- three counties with the largest Latino populations in Iowa. And, on his final day, Castro headlined an event in Storm Lake, a community that has become nationally known for its growing Latino community in the center of conservative Iowa.

Castro's pitch is sweeping and progressive, even if it is delivered in an understated manner.

As president, the former mayor said he would make extensive changes to health care, raise the minimum wage to $15 and reassert the United States' role in combating climate change by re-signing the Paris Climate Accord. He has also pledged wholesale changes to the immigration system, including blocking Trump's attempt to build a border wall, making it easier to become a citizen and "breaking apart and reconstructing" immigration enforcement.

And Latino voters in Iowa told CNN during Castro's trip that they believe the former mayor, whose grandmother was born in the Mexican border state of Coahuila and crossed into the United States at Eagle Pass, Texas, in 1922 after her parents died during the Mexican Revolution, has the political experience, policy positions and personal story to tap into their communities.

Castro told CNN during the trip that he was enthused by the response he got from these small communities and commended the Iowa Democratic Party for moving to provide a "virtual caucus" in 2020, allowing people who may not want to attend the traditional in-person caucus a forum to voice their opinion on the eventual Democratic nominee.

"I think you're going to get a number of people in the Latino community who are eligible to vote and caucus, but they may have a relative that is undocumented or have some reason that they don't want to stick their neck out," Castro said, adding that he believes it would protect people from "that fear potential repercussions for sticking their neck out because of immigration issues or others."

'You don't want to get attention'

Jose Ibarra, one of Storm Lake's six city council members, has personally lived this issue.

When Ibarra decided to run for the council in 2017, he wanted his candidacy to show other Latinos in the community that they, too, would be taken seriously in the state's political process.

That can be difficult, Ibarra said, in an area that has represented Steve King, a lawmaker who recently lamented the fact that the term white nationalism has been labeled offensive, since 2004. King was condemned for the comments and lost much of his standing in Congress after the controversy, but the impact of his repeated election in Northwest Iowa has depressed non-white voters in the area, said Ibarra and others.

Ibarra, who was born in Mexico, went on to win the city council seat and now represents part of the largest town in Buena Vista County, an area where more than 25% of all residents are Latino.

"As a Latino in a predominately white area, it is very hard," he said as Castro's event in Storm Lake. "But the reason I decided to run is because I wanted people to know that if a first-generation immigrant from Mexico who still has an accent, who still looks different, can run for office and win, it's huge."

But his experience is unique. Most Latinos in the community, Ibarra said, are far removed from the state's involved political process, something that has only been more apparent in response to Trump's administration.

Jeaneth Ibarra, the councilman's wife who came to the United States from Honduras in 1997, said that even for those Latinos in Northwest Iowa who are in the United States legally, getting involved in politics can be daunting, especially if your goal is to "just focus on work and go home."

"You don't want to get attention," Ibarra said of Latinos who know people who are in the United States illegally. "People are afraid that if you get attention, then ICE will get closer to a family member or friends of the family that are here illegal."

She added: "So because of that, people don't want to be bothered by what is outside their routine."

Castro, who greeted the audience in Storm Lake with a hearty "buenos dias" and left with a similar "muchisimas gracias," is familiar with Storm Lake. He campaigned for JD Scholten, the Democratic candidate for Congress who narrowly lost to King in 2018 and reminded the audience that he was not a first-time visitor.

Since Castro's last visit, though, fear among Latinos in the area had grown, said residents like Andrea Frantz, a professor at Buena Vista University who teachers a citizenship class on the side. Frantz has been teaching the class for years and usually gets around 15 people in each class. But in the last year, her class has had no more than three people.

"There has been a chilling effect in terms of public engagement on issues," Frantz said. "And when you think about what a caucus is, especially a face-to-face caucus, it can be a very intimidating process."

It's because of those fears, said Art Cullen, a journalist who won a Pulitzer Prize in 2017 for his editorial writing about the area, that Castro will be unlikely to do what past Democrats have failed to do.

"The entire community is deeply paranoid right now because, even people with papers are afraid of getting detained by ICE," Cullen said. "So, the few Latinos who were there, he really resonated with. But like Texas, Latinos just haven't risen up in these pockets."