The US is unique in this: No other nation that has taken in adopted children deprives them of citizenship.

In 2000, Congress acknowledged that injustice and passed the Child Citizenship Act, conferring automatic citizenship to adopted children. But it was designed to streamline the process for adoptive parents, not to help adoptees, and so applied only to those younger than 18 when it took effect. Everyone born before the arbitrary date of February 27, 1983, was not included.

Hannah Daniel, director of public policy for the Ethics and Religious Liberty Commission, the lobbying arm of the Southern Baptist Convention, said lawmakers often find this situation hard to believe.

“I agree that it feels unbelievable,” she said. “It’s the most classic example of wanting to bang your head against the wall, because how in the world have we not fixed this?”

Adoption has been a rare issue championed by lawmakers on both sides of the aisle, a way of saving children by making them American. Many churches preach intercountry adoption as a Biblical calling.

Daniel is part of a bipartisan coalition lobbying for a decade for a bill that extends citizenship to everyone legally adopted by American parents. The groups insist that families formed by adoption are due the same respect, the same rights, as biological ones, including equal treatment under the criminal justice system.

But that argument has been consumed by the country’s hyper-partisan frenzy over immigration. Any bills offering paths to citizenship have stalled out.

Republican Senator Chuck Grassley, among those sceptical of the legislation, declined an interview. A spokesperson wrote in a statement that he is “a longtime adoption advocate” but “believes that any adult seeking US citizenship should have their criminal records taken into consideration.”

That is a sentiment that advocates of the bill say undermines the very meaning of adoption. If a foreign adopted sibling and a biological sibling commit a crime together, the biological child would pay their debt to society and move on. The adopted child might face a second, severe punishment: getting sent back to where the US professed to have rescued them from.

A bill is before Congress again now. But Daniel isn’t hopeful.

“In this day and age in Congress, if not doing anything is an option,” she said, “that is the bet I’m going to take.”

Laura Lynn Davis called her representatives, her senators. She’s written to celebrities and talk show hosts, thinking surely someone would help. Mike Davis, her husband of 27 years, was adopted by a soldier, a Vietnam veteran stationed in Ethiopia, who met him there as a boy and brought him to the US

He was deported to Ethiopia two decades ago, and now lives in a room with a mud floor and running water only once a month and even when the tap works, it isn’t safe to drink.

Davis, now 61, remembers his father telling him that everything would be OK because he was an American now. He pledged allegiance to the flag every morning and considered himself a happy military brat, moving around Army bases.

“I was living the American dream,” Davis said.

He worked at a pizza shop through high school and when he graduated, he opened his own.

In the 1990s, he was charged with possession of a firearm, marijuana and cocaine. He didn’t go to prison; he was sentenced to 120 days in a boot camp program. He found out he’d never been naturalized when he reported to his probation officer.

Nothing happened for years. He married Laura Lynn, they had children to raise, and he pushed it to the back of his mind. Then one day in 2003, he closed his pizza shop and went to bed, someone banged on their door at 5 a.m.

“My kids were sleeping,” he said, “When they woke up, their dad was gone.”

He languished in a detention centre for over a year, terrified, because he had the same perception of Ethiopia as many Americans: The State Department advises its citizens to not go there because of unpredictable violence, kidnappings and terrorism.

Then officers took him to the airport and put him on a plane, he said. One officer felt sorry for him and gave him $20; Davis promised to pay him back when he returned to the US. He sold his wedding ring to pay rent, and that was the darkest moment. His adoptive father grew sicker, and Davis anguished over not being with him in the end.

His wife sold their house and moved their family to be with him. But life was hard in Ethiopia: There were people with M16s on the street, they couldn’t work or speak the language. Laura Lynn lost 30 pounds. She and their children went home to Georgia.

Mike was their breadwinner, and they struggled without him. They lived in cars and motels, but never blamed him. Laura Lynn kept all his things neatly packed and awaiting his return: clothes, sports memorabilia, his favourite music – on cassette tapes, a reminder of how the world changed since he left. He gets sick a lot as he’s getting older, she said, and can’t access medications in Ethiopia.

He has five grandchildren he’s never met. His youngest son, Adam, 26 now, recently moved into his first apartment, and thought how nice it would be to have his father there to see it.

Laura Lynn has more hope than she has in a long time, she said, because a group she never expected came to their aid: Koreans. They’ve offered advocacy and legal help. He’s being represented by groups like Asian Americans Advancing Justice and Adoptees for Justice.

“I pray we can make them see that he didn’t ask to come here, he was adopted and brought here. He became a really good man,” she said. “He has a family who loves him and we’re ready for him to come back home to US.”

Emily Howe, a lawyer in California, carries around a five-inch binder, which she calls “the simplified version” of the labyrinthine set of laws that dictate which adoptees have been able to become citizens and which have not.

Emily Howe was adopted from South Korea in 1984, barely young enough to be granted citizenship by the 2000 law. By a twist of luck and timing, this could have been her, she said. So she represents many adoptive families for free.

“It shouldn’t be a spin of the roulette wheel,” she said. She now asks every adoptee if they know their citizenship statUS It gets complicated quickly; if they ask the government and find out they aren’t citizens, they tip off authorities to them living here illegally.

Her clients are panicking about what will happen if Trump wins reelection.

“I’m terrified,” a mother named Debbie cried in Howe’s San Diego office. “What if he gets back in? I’m hearing him talk about mass deportations.”

• An AP report