Face down in the water, the bodies of a man and his little daughter float amidst flattened reeds on the banks of the Rio Grande. Her tiny arm droops over her father's neck, her small torso enveloped protectively inside his shirt.

The photo documenting the desperation of Salvadoran migrants who drowned while fleeing to Texas from Mexico has ricocheted across the internet. It has cut through the statistics-driven discourse about the immigration crisis at the southern border. It has provoked stunned responses from the Pope and the United Nations.

It has enraged Democratic presidential contenders like Beto O'Rourke, who blamed the deaths on U.S. President Donald Trump; Kamala Harris, who called Trump's policies "a stain on our moral conscience;" and Cory Booker, who similarly lashed out at Trump's immigration policies and remarked about the image, "We should not look away."

Yet some experts who spoke with CBC News doubt the photograph by journalist Julia Le Duc — powerful as it is — will result in lasting changes to policy. Nor do they think it will do much at all to sway hardened opinions on the polarizing topic of immigration in the United States.

Asked about the photo of the toddler and her father on the south lawn of the White House, Trump said Wednesday: "It's like I've been saying. If they fix the laws, we wouldn't have that."

WARNING: This section contains graphic images

Some Democrats have called for an increase in capacity at processing centres and a halt to the new policy known as "metering," by which the number of asylum seekers to the U.S. is capped per day, thus forcing migrants to wait weeks for entry or risk crossing illegally.

Trump has requested $4.5 billion in emergency funding to bolster border operations to deal with an influx of migrants arriving at the U.S. border with Mexico. The solution from the Democrat-controlled House was to pass a $4.5-billion emergency border aid package this week that would include billions for sheltering and feeding detained migrants, as well as care and legal services for unaccompanied minors. But it would deny Trump additional funding for Immigration and Customs Enforcement detention beds.

The White House threatened to veto the bill, saying it would hamstring border enforcement efforts.

This photograph, first published in the Mexican newspaper La Jornada, shows the bodies of Oscar Alberto Martinez Ramirez and his nearly two-year-old daughter Valeria on the bank of the Rio Grande in Matamoros, Mexico. CBC News has not independently confirmed the circumstances of their deaths. (Julia Le Duc/The Associated Press)

Alan Bersin, a former commissioner of U.S. Customs and Border Protection under president Barack Obama, said the U.S. is "in need of deep national soul-searching."

As with many on social media, he found the photo of the migrant father and daughter clinging to each other to be emotionally gutting, but the political divide over immigration isn't so easy to overcome, he said.

"I think the polarization is so complete in terms of people's views of the border, I'm skeptical as to whether or not this will move the needle, except to reinforce their pre-existing positions."

If the picture does spark more serious calls for immigration reform, research suggests those feelings could be short-lived.

University of Oregon researchers found that donations for the Swedish Red Cross spiked dramatically immediately after the release of a photo of Alan Kurdi, the three-year-old Syrian boy whose body washed up on a beach in Turkey during the migrant crisis in 2015. The image made headlines around the world.

But the donations dwindled over time.

The body of Alan Kurdi, 3, washed up on a Turkish beach on Sept. 2, 2015. Images of the tragedy sparked outrage and an outpouring of support for the plight of millions of displaced Syrian refugees.

In the same 2016 study, the researchers wrote that the iconic photo of Kurdi "had more impact than statistical reports of hundreds of thousands of deaths."

Unfortunately, they also concluded, the "newly created empathy waned rather quickly."

'A face to the story'

There are other examples of photographs having a major impact.

Photographer John Moore, a Getty Images special correspondent, took a photo last year showing a two-year-old Honduran girl at the southern border wailing as her mother was being searched and interviewed by border patrol officers.

The picture went viral.

It prompted an outpouring of financial support from Americans for families caught at the border. A Silicon Valley couple started a Facebook fundraising page for refugees that brought in more than $20 million.

This picture of a crying Honduran girl became a powerful image used to illustrate the controversial policy of separating children from migrant parents arrested for crossing the U.S./Mexican border. (John Moore/Getty Images)

This, despite Moore stating at the time that he did not know whether the mother and daughter would be subjected to the president's policy of family separation. In fact, they were not separated and were taken into custody together.

But the image, which was awarded the World Press Photo award for 2018, still resonated.

"That image was important to highlight the administration's zero-tolerance on the border," Moore said in an interview. "It put a face to the story that is often told in terms of statistics. It's important for us to humanize issues, to make them relatable to the public. And sometimes those are the tough images."

Images like the one that Moore saw this past week at the Rio Grande, showing the father, now identified as Oscar Alberto Martinez Ramirez, with his 23-month-old daughter, Valeria.

Photojournalist John Moore has been documenting migrant issues at the U.S. southern border for the last decade. He took an iconic photo of a two-year-old Honduran girl crying in 2018 as her mother was being questioned by border patrol officers. (Mario Tama/Getty Images)

CBC News has not independently verified how they came to meet their fate, but reports say the family from El Salvador grew frustrated by the wait times to be processed as refugees at the U.S. border. When the father started to swim across the river, his daughter reportedly jumped in after him. When he went to retrieve her, both were taken by the current.

Le Duc's photo, published in the Mexican newspaper La Jornada, tells the rest of the story.

"It's no doubt a powerful image and could potentially become iconic," Moore said. "I know some people have said it's an invasion of privacy, but I do believe photojournalism serves a powerful role in reflecting reality."

For Dutch filmmaker Misja Pekel, the photo of the drowned father and daughter at the Rio Grande immediately brought to mind the photo of Alan Kurdi.

Rosa Ramirez, mother of Oscar Alberto Martinez Ramirez, a migrant who drowned in the Rio Grande River with his daughter Valeria during their journey to the U.S., is pictured at her house in the Altavista neighbourhood in San Martin, El Salvador, on Wednesday. (Jose Cabezas/Reuters)

Pekel's 2017 film, Sea of Pictures, examined the global impact of the photo of the dead Syrian boy and its ability to snap a sleepy public to attention about the Syrian refugee crisis in Europe.

"This seems like the same thing," Pekel said of Le Duc's photo at the Rio Grande. "It's a picture we can identify with. It becomes much more connected to the world we live in."

Journalists have long reported on the overwhelming number of cases tied up in the immigration court system in the U.S., the months-long waits for asylum seekers to be processed, and the fewer than 450 judges on hand nationwide to handle the backlog of cases that exceeds 850,000.

'What's really going on'

But statistics can only go so far to further the public's understanding of the true nature of any problem, Pekel said.

"This picture tells us something on a very emotional level. These pictures make us aware of what's really going on," he said. "That's a shame that we need them, but we need them."

For a public that may be indifferent or numb to statistics, such images can crystallize a moment of crisis, said Michelle Mittelstadt of the Migration Policy Institute, a think-tank based in Washington, D.C.

Mexican authorities walk along the Rio Grande where the bodies of two Salvadoran migrants were found in Matamoros, Mexico. (Julia Le Duc/The Associated Press)

"It was really the power of that photo that brought home, in a tremendously visceral way for people around the world, what was at stake," she said.

At the very least, she said, it has brought fresh attention to an immigration crisis unfolding beyond where the media's eyes usually go.

In the case of reports about squalid conditions at an overcrowded Texas detention centre where nearly 700 children were being held in May before most were relocated, journalists could only do their best to describe the facilities, she said.

"Children without beds, without soap, without toothbrushes, without diapers — and the camera was not there."