(CNN) Imagine getting banned from seeing your dying child because of your nationality. Or watching your children get tear-gassed in front of you. Or trying to provide a better life for your 7-year-old daughter, only to have her die suddenly.
These horrors became reality for several families who have become reluctant faces of the US immigration debate.
Each case pits parents desperate to save their children against immigration policies aimed at tightening both illegal and legal entry into the United States. Here are their stories:
Two-year-old Abdullah Hassan isn't expected to live much longer. The toddler has a genetic brain condition, one that has kept him on life support at the University of California San Francisco's children's hospital.
Both Abdullah and his dad, Ali Hassan, 22, are US citizens. They were living in Egypt until October when Hassan knew his son knew needed urgent medical care. So they flew to California, only to learn Abdullah's condition is terminal.
But the child's mother, Shaima Swileh, is Yemeni -- meaning she wasn't allowed to visit the United States due to the Trump administration's travel ban against seven countries.
The agony has been overwhelming for Swileh, who was "literally crying every day" on the phone, her husband said.
The young father said his son is now near death.
"At this hour it is really bad," Hassan said Tuesday morning.
Hassan tried for weeks to get a special humanitarian visa for his wife that would allow her to see their son one last time. But the request has been slow to process, he said.
Shortly after Hassan spoke to CNN on Tuesday, his wife was granted a waiver to travel to the United States.
Yemeni mother wins visa fight to see her dying child in a California hospital
The Council on American-Islamic Relations-Sacramento Valley, which has been assisting the family, said the news is bittersweet.
"Unfortunately even with this win, it's still a loss," said Basim Elkarra, the group's executive director.
"At least she'll come and be able to mourn with dignity, and see her son get buried, and bring some closure to all the pain."
Elkarra praised "our fellow Americans" for raising funds to cover the mother's travel expenses and future funeral costs for her son.
Nery Gilberto Caal and his 7-year-old daughter, Jakelin, survived a grueling 2,000-mile trek from their native Guatemala to the New Mexico border.
The father and daughter had fled extreme poverty in Guatemala, leaving behind the rest of the family for a chance of a better life for the young girl.
But on December 8, less than 48 hours after getting detained by US Border Patrol agents, the young girl died. Caal still has no idea why his daughter's life was cut so short in the United States. And now members of Congress are trying to find answers, too.
Early indications from a hospital suggest Jakelin died from sepsis shock. But the local medical examiner has not determined the official cause of death, pending further studies.
Jakelin's dad has "no complaints about how Border Patrol agents treated him and his daughter," Guatemalan Consul Tekandi Paniagua said.
And in a statement released by his attorneys, the father said he was "grateful for the many first responders that tried to save young Jakelin's life in New Mexico and Texas."
Still, many questions remain about what happened while Jakelin was in custody, and whether asylum-seekers are treated appropriately.
On Tuesday, a congressional delegation is visiting the Customs and Borders Protection station where Jakelin was taken before she died in a hospital.
Eleven members of the House of Representatives will tour the station in Lordsburg, New Mexico, a congressional aide told CNN.
US Rep. Joaquin Castro, D-Texas, has said he wants a "full investigation by the Inspector General and Congress into the conditions and circumstances that led to (Jakelin's) death."
While it's still legal for migrants to seek US asylum, the odds of gaining asylum are now a lot tougher.
Under a recent Trump administration policy, those claiming a fear of domestic violence or nongovernmental gang violence will be rejected.
Still, Castro said, migrants such as Jakelin must be able to seek asylum safely.
"We have a moral obligation to ensure these vulnerable families can safely seek asylum, which is legal under immigration and international law at our borders," he said.
Of all the recent images of migrants at the border, one is seared into many Americans' minds: a mother on the Mexican side of the border yanking her diaper-clad daughters away from tear gas fired by US authorities.
Now, the woman in photo -- Maria Lila Meza Castro -- and her children have filed for asylum and are allowed to stay in the United States temporarily, said US Rep. Jimmy Gomez, D-California.
The family was among more than 100 migrants near the border November 25 when a few men tried to dismantle a wire fence separating the two countries, said Reuters photojournalist Kim Kyung-Hoon, who shot the image.
Authorities said tear gas was used to dispel the group after some migrants threw projectiles at agents.
After the incident, Trump threatened to close the border "permanently if need be." But so far, that hasn't happened, and critics say a full closure of the US-Mexico border would deal a huge blow to the US economy.