Two nations physically and culturally come together in El Paso. The bustling Walmart on the city’s east side, just minutes from the border with Mexico, exemplified those ties.

The store was a border version of Middle America: A large number of Mexican-American families from El Paso crowded into the megastore daily for inexpensive groceries and, late in the summer, back-to-school supplies.

Almost as often, families from Mexico drove across the international bridge to buy bargain TVs, cartons of nappies and discount clothing.

It was one of the company’s top 10 in America: Where most stores of its kind average 14,000 customers a week, the El Paso Walmart, a retail analyst said, saw 65,000.

Its racks are stocked with Mexican football jerseys, cans of chillies and salsa and Mexican flags, folded beneath the American and Texas flags on display. The pharmacy’s staff members are fully bilingual.

El Paso mass shooting: 20 killed at Walmart store Show all 39 1 /39 El Paso mass shooting: 20 killed at Walmart store El Paso mass shooting: 20 killed at Walmart store CCTV images of the gunman identified as Patrick Crusius The 21 year old, as he entered the Cielo Vista Walmart store in El Paso. The gunman was armed with an assault rifle and opened fire on shoppers at a packed Walmart store, killing 20. KTSM 9/AFP/Getty El Paso mass shooting: 20 killed at Walmart store Law enforcement agencies respond The Texas city’s police chief said the assault on a Walmart store on Saturday, which left another 26 people wounded, was being investigated as a potential hate crime. AFP/Getty El Paso mass shooting: 20 killed at Walmart store Shoppers exit with their hands up Shoppers exit with their hands up after a mass shooting at a Walmart in El Paso, Texas, U.S. August 3, 2019. REUTERS/Jorge Salgado NO RESALES. NO ARCHIVES. STRINGER Reuters El Paso mass shooting: 20 killed at Walmart store FBI released a picture of gunman Patrick Crusius The police officially identified the 21-year-old white male from Allen, Texas, a Dallas suburb some 650 miles east of El Paso. FBI/AP El Paso mass shooting: 20 killed at Walmart store A woman reacts after the mass shooting The attack came just minutes after a far-right manifesto appeared online. If authentic, it would make it the third mass shooting this year announced in advance on the website, which often features far-right and racist content. Reuters El Paso mass shooting: 20 killed at Walmart store Law enforcement responds to the active shooter The racist four-page document, titled “The Inconvenient Truth”, calls the Walmart attack “a response to the Hispanic invasion of Texas” and expresses support for the gunman who killed 51 people at two mosques in Christchurch, New Zealand earlier this year. AFP/Getty El Paso mass shooting: 20 killed at Walmart store A shopper hiding with an old lady behind the return and exchanges counter as the shooting began. Aaron Castaneda/Reuters El Paso mass shooting: 20 killed at Walmart store Ambulances in the car park near the scene It is ranked as the eighth-deadliest mass shooting in modern US history, after a 1984 shooting in San Ysidro, California, that claimed 21 lives. AP El Paso mass shooting: 20 killed at Walmart store Kendall Long (left) comforts Kianna Long (right) who was in the freezer section of Walmart. EPA El Paso mass shooting: 20 killed at Walmart store epa07755367 Police stand at attention after a shooting at a Walmart in El Paso, Texas, USA, 03 August 2019. According to reports, at least one person was killed and at least 18 people injured and transported to local hospitals. One suspect is in custody. EPA/IVAN PIERRE AGUIRRE IVAN PIERRE AGUIRRE EPA El Paso mass shooting: 20 killed at Walmart store Shoppers exit with their hands up. Reuters El Paso mass shooting: 20 killed at Walmart store Shopping carts sit next to a curb after the shooting. EPA El Paso mass shooting: 20 killed at Walmart store El Paso Fire Medical personnel arrive at the scene. AP El Paso mass shooting: 20 killed at Walmart store Walmart employees react after. AP El Paso mass shooting: 20 killed at Walmart store A woman runs to police near the scene. AP El Paso mass shooting: 20 killed at Walmart store Several law enforcement agencies respond. AP El Paso mass shooting: 20 killed at Walmart store People arrive at MacArthur Elementary looking for family and friends as the school is being used a re-unification centre. AP El Paso mass shooting: 20 killed at Walmart store Residents Erica Rios, 36, and Alma Rios, 61, cry outside a reunification centre. AFP/Getty El Paso mass shooting: 20 killed at Walmart store People gather in Juarez, Mexico, in a vigil for the Mexican nationals who were killed. AP El Paso mass shooting: 20 killed at Walmart store A child takes part in a vigil in Ciudad Juarez AFP/Getty El Paso mass shooting: 20 killed at Walmart store Francisco Castaneda joins mourners taking part in a vigil at El Paso High School. Reuters El Paso mass shooting: 20 killed at Walmart store Presidential candidate and former congressman Beto O'Rourke, right, meets with mass shooting survivor, Rosemary, at University Medical Centre Beto O'Rourke Facebook via AP El Paso mass shooting: 20 killed at Walmart store From left, Melody Stout, Hannah Payan, Aaliyah Alba, Sherie Gramlich and Laura Barrios comfort each other during a vigil for victims of the shooting. AP El Paso mass shooting: 20 killed at Walmart store A sign is posted near the scene Getty Images El Paso mass shooting: 20 killed at Walmart store Police cars parked below the Walmart sign block a road outside while investigating. EPA El Paso mass shooting: 20 killed at Walmart store Sherie Gramlich reacts during a vigil. AP El Paso mass shooting: 20 killed at Walmart store A man places flowers at the site Reuters El Paso mass shooting: 20 killed at Walmart store People take part in a rally against hate a day after a mass shooting at the Walmart store Reuters El Paso mass shooting: 20 killed at Walmart store Lupe Lopez holds a picture of a victim during a vigil for victims AP El Paso mass shooting: 20 killed at Walmart store People take part in a rally against hate a day after a mass shooting at a Walmart store, in El Paso, Texas, U.S. August 4, 2019. REUTERS/Jose Luis Gonzalez JOSE LUIS GONZALEZ REUTERS El Paso mass shooting: 20 killed at Walmart store Elsa Mendoza Marquez, a Mexican schoolteacher who was married and the mother of two adult children, was one of the victims Getty El Paso mass shooting: 20 killed at Walmart store People with the Mexican flag and the US flag take part in a rally against hate a day Reuters El Paso mass shooting: 20 killed at Walmart store People raise their arms in the air during a vigil for victims AP El Paso mass shooting: 20 killed at Walmart store People react and embrace each other Getty El Paso mass shooting: 20 killed at Walmart store Women light candles at a make shift memorial at the site of a mass shooting EPA El Paso mass shooting: 20 killed at Walmart store Adria Gonzalez (centre) who is being hailed as a hero for leading some Walmart customers to safety, speaks to the crowd AFP/Getty El Paso mass shooting: 20 killed at Walmart store People hold up their phones AFP/Getty Images El Paso mass shooting: 20 killed at Walmart store Beto O'Rourke speaks to the crowd AFP El Paso mass shooting: 20 killed at Walmart store People react during a prayer and candle vigil organized by the city, after a shooting left 20 people dead at the Cielo Vista Mall WalMart in El Paso, Texas, on August 4, 2019. - A shooting at a Walmart store in Texas left multiple people dead. At least one suspect was taken into custody after the shooting in the border city of El Paso, triggering fear and panic among weekend shoppers as well as widespread condemnation. It was the second fatal shooting in less than a week at a Walmart store in the US and comes after a mass shooting in California last weekend. (Photo by Mark RALSTON / AFP)MARK RALSTON/AFP/Getty Images MARK RALSTON AFP/Getty

“It really does feel like a United Nations store,” said Burt Flickinger, a retail consultant who has visited and studied the store.

This is the border as it is lived everyday, far from the heated national debate over immigration. Children come and go across the international boundary for school, others come for jobs and shopping.

It was in this Walmart, on a sunny Saturday morning, where a white gunman angered by what he called the “Hispanic invasion of Texas” chose to carry out a horrific act of violence.

Disturbed gunmen have previously targeted American Jews, African Americans, Muslim-Americans, gay Americans and American journalists.

Authorities say the El Paso gunman, identified as Patrick Crusius, 21, targeted Mexican and Mexican-American shoppers and workers in the attack on Saturday, killing 20 people and wounding 27 others.

While there have been numerous Hispanic victims in several of the mass shootings that have shocked the nation in recent years — including the Pulse nightclub attack in Orlando, Florida, in 2016 — the massacre in El Paso was the deadliest anti-Latino attack in modern US history.

The manifesto that a federal law enforcement official said Mr Crusius wrote and posted online minutes before the shooting made his anti-immigrant beliefs clear.

He wrote that immigration “can only be detrimental to the future of America,” and bemoaned a future in which Hispanics would take control of the local and state governments, “changing policy to better suit their needs”.

The apparent anti-Latino motive behind the attack stunned residents and officials, who saw the nation’s fraught debate over culture and immigration erupting with sudden violence in a city that had been both a focal point of immigration and a place — like many border towns — where the notion of immigration and national identity had rarely felt divisive.

“What was most shocking to me is not that it was a mass shooting but the motive, the fact that he specifically targeted Mexican-Americans and Hispanics,” said Gilda Baeza Ortega, 67, a librarian at Western New Mexico University who was in El Paso visiting her parents. “He came here for us.”

Across the country, many Latinos were describing the targeted killings as a 11 September moment, and the FBI’s announcement Sunday that it had opened a domestic terrorism investigation only reinforced that belief, especially in a city that is 80 per cent Hispanic.

The El Paso community was defiant in the wake of an attack that socked a nation to its core (Getty Images)

“This Anglo man came here to kill Hispanics,” El Paso’s sheriff, Richard Wiles, said. “I’m outraged, and you should be, too. This entire nation should be outraged. In this day and age, with all the serious issues we face, we are still confronted with people who will kill another for the sole reason of the colour of their skin.”

Before the attack upended the sense of normalcy in El Paso, the Walmart and the shopping area surrounding it lured many people from across the border, as well as many El Paso residents looking for something to do on a weekend afternoon.

People from both countries would go to new releases at a cinema not far from the Walmart, shop for discount clothing at a nearby Ross Dress for Less or stop in for happy hour at Hooters.

Texas has long been a state where Hispanics have shaped and in many ways defined what it means to be Texan. But in recent years, the old white Texas and the new Hispanic Texas have repeatedly clashed.

Some of this tension involves who gets to tell history. Activists and scholars have begun focusing on the legacy of racist campaigns of terror against Latinos in this part of the West, including the killings a century ago of Mexicans by lynch mobs made up of Anglos.

Going back further in the debate over any “invasion of Texas,” historians note that it was actually carried out by Anglo slaveholders who migrated to the region in the 19th century when it was still part of Mexico, then seceded in 1836 and enshrined white supremacy in the first Texas Constitution.

The more recent clashes have led not only to years-long court battles but also to physical confrontations between white and Hispanic politicians on the floor of the Texas House of Representatives.

White Republican officials in Texas have publicly expressed alarm about what they describe as an “invasion” of migrants spreading disease at the Texas border.

El Paso residents have now seen the most hateful parts of the debate bringing violence to their doors.

Adriana Ruiz was among those who left flowers, having picked up a bouquet from another Walmart in El Paso after church.

“I just...” she said, her voice trailing off. “Right now, my heart is broken.”

Families gather at the scene of the El Paso shooting as a chorus of calls for a US gun control clampdown grow louder (REUTERS)

Ms Ruiz, 50, said she was pained by the animosity that had surrounded the national debate about El Paso as it became a ground zero of sorts in recent months as migrants came rushing in from Central America.

A hateful act seemed like such a stark contrast to the vibe and texture of the city where she was born and raised. She remembered going to Ciudad Juarez in Mexico on Saturdays with her mother, grandmother and aunts to go shopping.

“No matter who it is,” she said. “We make them feel at home.”

The shooting, she said, showed that a toxic environment outside El Paso was finding its way into the city. She heard it in the remarks about life in the city that did not reflect what she knew, especially those from Donald Trump, the US president.

“That is something that came from the top,” Ms Ruiz said, referring to the frequent portrayal of the border as a place of crisis that was threatened with invaders from outside.

“It’s idiotic,” she said, conceding that her anger had left her stumped for the right words. “I want to say some harsher words, but it’s not right."

Larry Scott, 40, said he had been in the Walmart on Saturday morning, several hours before the shooting. He had gotten two new tattoos on his left arm recently, including one of the Monopoly man holding a bag of money, and he needed ointment.

When he heard about the attack, Mr Scott, who said he serves in the Army and is stationed at nearby Fort Bliss, felt an urge to do something, to somehow pitch in. He came back to the store Sunday, but that offered little consolation.

El Paso was not his hometown. He was originally from Dallas, he said. Yet he had grown attached to the city.

“It’s not a big city,” he said. “But it’s our home. I’m hoping this makes El Paso stronger.”

Military man hailed as a hero after carrying as many children as he could to protect them from El Paso shooter

The Walmart where the shooting occurred lies on the east side of El Paso along Interstate 10, near a number of hotels, chain restaurants and a mall.

Aside from the wares that are aimed at Mexican shoppers, it resembles hundreds of other Walmarts across America. The store does not sell guns, but does sell ammunition, a Walmart spokesman, Randy Hargrove, said.

On Sunday, the store remained blocked off by police officers who continued to collect evidence of the massacre inside. The parking lot was still packed, with the same cars that had been sitting there since the shooting the day before.

A steady line of cars drove by, some with cameras pressed to their windows. One man walked up, stood silently for a moment, made the sign of the cross and walked away.