LINCOLN, Neb. — Roberto Rodriguez works at a meatpacking company in Nebraska's capital. For years, most of his colleagues were fellow Mexicans and Central Americans. These days, the men standing by his side increasingly are Middle Easterners.

"We communicate through hand signals," said Rodriguez, who came here from his native state of Zacatecas. "Working with Arabs is something I never thought I'd be doing. I thought the pipeline of Mexicans was forever."

Several times a day, his Muslim colleagues pause to pray. He finds the breaks a bit odd, even annoying, but he's willing to cut his co-workers some slack.

"I think we Mexicans pray all the time too, especially when you work in the meat industry," he said as he made the sign of the cross. "I try to be as welcoming as possible because I think we understand rejection."

In Lincoln, the face of immigrant labor is changing. Workers are harder to come by, and immigrant labor is no longer the exclusive domain of Mexicans and Central Americans.

It's a dynamic playing out across the U.S.

By 2020, the private sector will be facing a shortage of 7.5 million workers, said Ali Noorani, of the National Immigration Forum, a Washington-based think tank, citing a study by the American Action Forum, a moderate policy institute that promotes rights for immigrants. And the U.S. had the fewest newborns last year since 1978, according to a new report by the Centers for Disease Control and Prevention. The worker shortage is only likely to get worse.

"We are increasingly dependent on a combination of documented and undocumented workers, refugees with temporary worker status," said Noorani, author of There Goes The Neighborhood, a book that examines the changing demographics in the U.S.

1 / 3Students from Iraq, Mexico and China took pictures together after the last class of a Lincoln Literacy summer session at Culler Middle School in Lincoln, Neb., on Wednesday, July 12, 2017. Lincoln Literacy is a nonprofit formed to teach the English language to immigrants and refugees arriving in the city. (Matt Ryerson/Special Contributor)(Matt Ryerson / Special Contributor) 2 / 3In a classroom located backstage of an auditorium, volunteer tutors Kezie Mwaniki (far left) and Daniel Otto (left) speak to their class including people from Iraq, Mexico, Ukraine, Ethiopia and China during a Lincoln Literacy class at Culler Middle School in Lincoln, Neb. on Wednesday, July 12, 2017. Lincoln Literacy is a nonprofit formed to teach the English language to immigrants and refugees arriving in Lincoln. (Matt Ryerson/Special Contributor)(Matt Ryerson / Special Contributor) 3 / 3Erika Calleja of Morelos, Mexico, laughs at a comment made by her tutor while attending class with Elifenesh Bizuenh of Addis Abela, Ethiopia, (middle) and Graciela Perez of Chihuahua, Mexico, (far right) during a Lincoln Literacy class at Culler Middle School in Lincoln, Neb. on Wednesday, July 12, 2017. Lincoln Literacy is a nonprofit formed to teach the English language to immigrants and refugees arriving in Lincoln. (Matt Ryerson/Special Contributor)(Matt Ryerson / Special Contributor)

The think tank's more conservative counterparts at the Center for Immigration Studies, which favors stronger immigration controls, argue that higher wages would lure more American workers.

So-called labor shortages, argued Mark Krikorian, executive director of CIS, "is a sign, information for the employer that they need to change their way of doing business. They need to consider things like automation, change their recruiting strategies. Pay higher wages and offer better benefits, like free van shuttle service to pick up workers."

Krikorian is also opposed to a temporary guest worker program, saying "there is nothing more permanent than a guest worker. People are not widgets. Eventually they will want to settle down."

Rolling out the welcome mat

Some companies in the Midwest are literally rolling out the welcome mat for immigrants and refugees. Muslim prayer rooms, complete with rugs, have been installed for Middle Eastern workers. Some employers help workers enroll in English classes. Others push for a more robust guest worker program to fill jobs once filled by Mexican laborers.

"We don't have enough labor to meet demand," said Clayton Naff, executive director of the Lincoln Literacy Council. "We are a major resettlement place for refugees, a magnet for immigrants, and like all America, we have many new Americans trying to integrate. We need workers to keep our community thriving."

With baby boomers retiring and U.S. birth rates and migration from Mexico falling, the nation is relying on a mixture of immigrants and refugees to keep its labor force growing.

Immigrants make up about 17 percent of the U.S. labor force, with about one-quarter of those undocumented. Without the current rate of both legal and undocumented immigration, the total U.S. workforce would shrink dramatically over the next 20 years, according to a 2017 study by the Pew Research Center.

Many industries, particularly agriculture and construction, are already taking a big hit, said economist Pia Orrenius, an expert on labor and demographic changes at the Federal Reserve Bank of Dallas.

For example, Hurricane Harvey is challenging the building industry everywhere as workers head to Houston to rebuild the city, she said.

"What we are seeing everywhere is a tight labor pool that's increasingly drying up and putting pressure on employers, leaving them in a bind," Orrenius said. "The future workforce is moving away from undocumented workers because those workers are no longer there. Fewer are coming across the border. The economy will find a way to readjust somehow, but in the end consumers, who once benefited from undocumented workers, will pay more."

Not long ago, jobs, particularly in the labor intensive meatpacking industry, went almost exclusively to Mexicans and Central Americans. But with fewer Mexican immigrants migrating illegally to the United States, refugees seeking a safe haven in the U.S are taking their place. The gradual departure of Mexican workers is opening up new opportunities.

The decline is fueled by a demographic shift in Mexico, including a lower birthrate and aging population, tighter border enforcement under the Trump administration and a fierce anti-immigrant mood in much of the U.S. In addition, the journey north has become increasingly dangerous with human smuggling linked to drug cartels on the rise.

The decline in the Mexican birthrate coincides with that of the United States. In 2016, the U.S. fertility rate was the lowest on record, continuing a long-term decline of 67 percent since 1991.

Meatpacking companies have tried recruiting whites and African American workers in Minneapolis, Chicago and Kansas City and most last longer than a week, said Don Stull, an anthropologist and professor emeritus at the University of Kansas who has long studied the beef and poultry industry.

Nebraska Gov. Pete Ricketts spoke to President Donald Trump during a meeting on trade with governors and members of Congress at the White House on April 12, 2018, in Washington. (Photo by Chris Kleponis - Pool/Getty Images) (Pool / Getty Images)

Stull says that when he meets with ranchers, meatpacking owners, etc., over coffee, they frequently tell him they hope that President Trump is not serious about building a border wall because they need immigrant workers to keep coming to the U.S.

"Now we're being nostalgic for Mexicans — the same ones we once complained about — and now the same employers who voted for Trump want them back," Stull said. "That doesn't surprise me, and yet they want the wall. I don't get it. Humans are inconsistent beings."

Despite politics that tend to be red, Nebraska and other communities in the Midwest and Great Lakes Region appear to be defying the vitriolic debate over immigration nationwide, albeit quietly. In Lake Geneva, Wis., Mexican kitchen workers battered, broiled and baked the ingredients for the traditional Fish Fry Friday.

Mexicans also toil in the dairy farms, and mow miles of home lawns and golf courses near Lake Como, Williams Bay and Kenosha, a region that Trump showcases to tout his "America First, Hire America" message. The picturesque region is a popular vacation spot with Chicagoans, and draws thousands of immigrants for the hospitality industry.

"The key is to keep a low profile," said Santos, an undocumented worker who did not want his last name used. He and his wife have lived in Wisconsin for 21 years, where they have raised a family of four, including three children born in the U.S. They own and run a landscaping company.

Midwest attracts immigrants

In St. Paul, Minn., a network of workers from Axochiapan in the southern Mexican state of Morelos owns restaurants, bakeries and tortillerias alongside Asian and Muslim eateries and businesses. The state is home to the largest Somalian community in the United States and some 185,000 Mexican workers.

"I would say Minnesota — the Midwest in general — is progressive in understanding the contribution of immigrants, refugees," said Gerardo Guerrero, the Mexican consul general in St. Paul.

1 / 2The corner of S 11th and G streets, known as Klein's Corner, is a melting pot of cultures in Lincoln, Neb., on Wednesday, July 12, 2017. The area includes a Mexican bakery, a liquor store, a small market and an Italian restaurant. (Matt Ryerson / Special Contributor) 2 / 2An Audi pulls into the market at the corner of S 11th and G Streets, known as Klein's Corner, in Lincoln, Neb. on Wednesday, July 12, 2017. The area includes a Mexican bakery, a liquor store, a small market and an Italian restaurant. (Matt Ryerson/Special Contributor)(Matt Ryerson / Special Contributor)

The anti-immigrant mood across the country hasn't gone unnoticed by immigrants, an increasing number of them transplants from Texas putting down roots in the Midwest.

"I think Nebraska in general is less hypocritical than other states," said Ignacio Chacon in Omaha.

Chacon formerly worked in Texas. He pours cement for up to nine hours a day before working as many as six hours in the evening as a busboy at a high-end restaurant.

"As long we're not too visible, remain invisible, we're fine," he said. "But here no one seems to be talking about targeting us. In fact, employers continuously ask me and others to recruit friends and family from Mexico because they need more workers."

Movement within the country

Lissette Aliaga-Linares, an associate professor of sociology and Latin American studies at the University of Nebraska at Omaha, said she is seeing fewer Mexicans coming from their native country. Instead, she's seeing a rising number of disgruntled Mexicans leaving states because of the high cost of living or fleeing controversial measures such as Texas' sanctuary cities law.

"We don't ask people whether they're from Mexico anymore," she said. "But whether you're from California, because the cost of living is too expensive, or these days from Texas, because many Mexicans don't feel very welcomed there anymore, we're seeing a lot of internal migration."

Sandra Rojo is new to Lincoln, where she works as English as a Learning Language coordinator at the Literacy Council. She once worked near Dallas and finds more Texans moving into the area. "I tell them this is home because you feel wanted, welcomed here."

In her classroom, she teaches Mexicans, Africans, Vietnamese and Middle Easterners: "Different cultures, backgrounds, but we come for the same reason. We're all looking for a better life and to contribute to this country."

Daniel Otto, a Sudanese refugee, student at the University of Nebraska and volunteer at the Lincoln Literacy Council, agreed. "We're the future workforce — Arabs, Vietnamese, Mexicans, people of different faiths. Everyone's tolerance is being tested."