On paper, Chris Young seems exactly the kind of person a prison reform bill ought to release from federal custody.

In the eight years since he was last free, Young has become an avid reader, taught himself to write computer code and worked as a tutor for fellow prisoners. Right now he’s reading Yuval Noah Harari’s Homo Deus “for fun”. He also says that since he can’t get real-world practice, he re-reads the same passage of a programming book every day after lunch, to make sure it’s committed to memory.

When he was 22, Young was arrested on a third low-level drug charge. Under so-called “three strikes” laws, he was given a mandatory life sentence. For decades, in cases involving repeat drug offenders, such laws have stripped federal judges of discretion. The judge who sentenced Young, Kevin Sharp, was so shaken by the experience he retired shortly after.

“What I was required to do that day was cruel,” Sharp tweeted earlier this year.

I’m human and I would have loved to have benefited from the bill, but unfortunately I don’t Chris Young

The bipartisan First Step Act, signed into law by Donald Trump on Friday, softens that “cruel” requirement for federal judges, reducing the mandatory sentence in such cases to 25 years. But it will not do anything for Young. In one of many compromises made by progressive reform advocates to secure conservative support, this and several other provisions were not made retroactive.

“I’m human and I would have loved to have benefited from the bill, but unfortunately I don’t,” Young told the Guardian from federal prison in Lexington, Kentucky. “I don’t necessarily feel left behind, I just feel [lawmakers] don’t understand what goes on with the … actual humans that their choices and politics affect.”

“A tough pill to swallow”

At a signing ceremony on Friday, Trump said the act “will make communities safer, save tremendous taxpayers dollars. It brings much needed hope to many families during the holiday season.”

Kevin Ring, president of Families against Mandatory Minimums, which heavily lobbied heavily for the bill called the signing “a small first step, but it is finally a step in the right direction.”

The result of painstaking coalition-building in a rancorous political climate, First Step earned support from politicians as ideologically diverse as senators Kamala Harris and Ted Cruz, and from advocacy groups including the American Civil Liberties Union and the Fraternal Order of Police.

The act expands rehabilitative opportunities, increases “good time”-served credits for most federal prisoners, reduces mandatory minimum sentences for a number of drug-related crimes, and formally bans some startling correctional practices, such as the shackling of pregnant women.

A conservative Republican Senate has just given permission to conservatives to engage in criminal justice reform Glenn Martin

“This victory truly belongs to the thousands of people who, like me, have been personally impacted by incarceration and have dedicated their lives to improving the system.” said Jessica Jackson-Sloan, national director and cofounder of #cut50, the primary reform group behind bill. “This bill was informed by their experiences. Their stories helped win over the president’s support.”

Advocates believe it can be a launching point for state and local reform which could have a much greater impact on the US inmate population. After all, just 10% of people incarcerated in the US are in the federal system.

“I absolutely think that this one is going to be catalytic towards other de-carceration campaigns on the local and state level,” said Glenn Martin, a formerly incarcerated reform advocate who helped bring dozens of former inmate-led groups on board for the First Step Act.

“I think that the Senate – a conservative Republican Senate – has just given permission to conservatives all over the country [to become] engaged in criminal justice reform.”

Nonetheless, the lack of retroactivity on a majority of the sentencing reforms was “a tough pill to swallow”.

“It’s one of the concessions that hurts the most,” said Martin. “It’s about fairness, and yet there’s this group of people who continue to be harmed because of the lack of retroactivity.”

That includes people like John Bailey, a 71-year-old inmate of the federal prison in Hazleton, West Virginia which is nicknamed “misery mountain”. Bailey’s brother Oliver said he was struggling to understand the logic of the changes not applying to inmates like John, who was imprisoned in 1992 on a non-violent drug charge.

“If you recognize the injustice now,” asked Bailey, “how come it doesn’t apply to those that suffered the same injustice before?”

Advocates who worked on the bill said conservatives and politically vulnerable Democrats opposed retroactivity because of how releasing prisoners early might resonate with voters.

There is one bright spot for the Baileys. One provision of First Step that does apply to current inmates is a requirement that prisoners be housed no more than 500 driving miles from their home. Bailey, who is from St Petersburg, Florida, has spent his prison life in Leavenworth, Kansas and now West Virginia, thousands of miles away. Oliver has not seen John since he was jailed.

“At this point something’s better than nothing,” he said. “We need to progress from here.”

If you recognize the injustice now, how come it doesn’t apply to those those that suffered the same injustice before? Oliver Bailey

It’s a common sentiment. Chad Marks is serving a 40-year sentence on drug conspiracy charges, thanks to another provision First Step will restrict. Marks’ sentence was enhanced by “stacking” language in federal law which dramatically increases a sentence if an offender possesses a firearm in the commission of a drug crime, whether or not it is used.

“I don’t understand how lawmakers can say that doing this is wrong,” he said, “and that they are going to fix it, but not apply it retroactively. That was a big blow. What has my focus and attention right now is the fact that lawmakers did something, but my focus is also on a second step coming.”

‘I just wanna come home and die’

Before her husband Ron died from colon cancer while in federal prison, Debra Cupp made him a promise.

“He said, ‘Dee, promise me that you’ll keep fighting so nobody’s family has to go through this again,’” she said.

The two tried to obtain compassionate release for Ron, a process First Step will make much more accessible. Previously, only sick inmates themselves could file paperwork, without access to counsel or loved ones. Cupp, from Virginia, said that was difficult for her husband, who often could not even come to the visiting room to see her because he was so ill.

“It was horrifying and heartbreaking because every time I talked to him he’d say ‘I just wanna come home and die,’” she said. “I would just be in tears because I felt so helpless.”

Even though First Step has addressed the issue, Cupp is not done. In her senator’s office, she said, she told staffers: “Remember my name – I’ll be back.”

Young, Bailey and Marks continue to wait for a second step. While they do, all three must place their primary hope for release in an act of clemency: a pardon or commutation issued by the president. Young’s case has been endorsed by Kim Kardashian, who successfully lobbied for the release of another federal prisoner, Alice Johnson, in June.

Marks said he was “more than hopeful that I will find relief through clemency”.

“I am praying that president Trump will find me worthy of mercy and grace,” he said. “I won’t let him down or disappoint him.”