President Barack Obama pauses as he speaks at the El Reno Federal Correctional Institution in El Reno, Okla., Thursday, July 16, 2015. AP Trenton Copeland was just 28 when he was told he'd spend the rest of his life in prison for a cocaine offense. He froze in shock the moment the judge read out the sentence.

It seemed like an impossibly severe penalty.

"It was almost like the world just stopped completely," his mother Annie Fray told Business Insider. "Life in prison, and he didn't kill anybody, for drugs? That is very devastating."

In 2011, Copeland was found guilty of conspiring to distribute and possess more than five kilograms of cocaine. Because of his prior drug offenses, Copeland's crime carried a mandatory life sentence without possibility of parole as per federal law — policies which have since been changed in certain cases, and would likely leave Copeland with a less severe punishment were he sentenced today.

Now, Copeland's only hope of securing a release is pinned on President Obama and the remaining three months of his presidency.

Like thousands of federal inmates serving time for non-violent drug offenses, Copeland is waiting to see if he will be granted a commutation — a reduction of a prison sentence — before time runs out. Over the last 8 months, the Obama Administration has granted dozens and sometimes hundreds of prisoners' commutations at a time in an unprecedented use of the president's constitutional clemency power.

Early in October, Obama commuted the sentences of more than 100 inmates, bringing his total to 774 commutations meted out over his eight-year term. It's more than the amount granted by the previous 11 presidents combined, and more than his successor will likely grant. Democratic nominee Hillary Clinton has not specified whether she will make clemency the priority that Obama has, and her opponent Donald Trump has expressed contempt for the initiative, calling the nonviolent drug offenders whose sentences were commuted "bad dudes."

In August, Deputy Attorney General Sally Q. Yates said that the Office of the Pardon Attorney, which reviews clemency applications and recommends them to the president, will act on "every single drug petition" it has. As of October, 13,275 petitions remain pending.

Urgency is mounting as the weeks go by, according to lawyers and advocates involved in the presidential clemency process. Clemency Project 2014, a countrywide network of lawyers who vet and forward inmates' petitions to the Pardon Attorney, has vowed to keep filing inmates' petitions until the last moment possible — so far, the group has whittled down some 33,000 applicants to around 1,700 petitions they deem viable.

“We certainly have expressed to [the lawyers] that time is of the essence and we want to work quickly and efficiently,” project manager Cynthia Roseberry told Business Insider.

The pace is only getting more frenzied as Obama's last day in office approaches, said Amy Povah, the founder of CAN-DO, a nonprofit that advocates for clemency applicants. CAN-DO communicates daily with hundreds of inmates and their family members regarding their petitions, according to Povah, who herself was granted a commutation by President Bill Clinton in 2000.

"The pressure is incredible, and it's increasing exponentially," she told Business Insider. "People are starting to panic."

Mancer Barrington III Courtesy of Mancer Barrington. A "once in a lifetime" opportunity

Mancer Barrington III was given a life sentence in 2008 for possessing and conspiring to distribute crack cocaine. Two months ago, he became one of the 774 petitioners granted a sentence commutation by Obama.

Like the inmates whose applications are still pending, Barrington feared that his petition wouldn't be acted on before Obama left office, even though his lawyers filed it more than a year ago. He recalled an agonizing wait leading up to Aug. 30, the day his lawyers phoned him with the news.

"We don’t know if the next President will continue what President Obama is doing," Barrington told Business Insider in an email.

His case is unusual even within the minority of inmates whose commutation petitions are granted. Barrington was not released from prison immediately when his commutation was granted. Instead, Obama reduced his life sentence to 15 years, leaving him with an expected release date of December 2020 with good time credit factored in.

As has been the case with dozens of other inmates in the past three months, Obama has been reducing the length of sentences, rather than releasing inmates immediately — a tactic that flies in the face of traditional clemencies.

By granting commutations in this way, Obama is in effect enacting his own piecemeal sentencing reform. His commutations have recalculated sentences for inmates — like Barrington — who were convicted under harsh sentencing guidelines enacted by Congress in the 1980s during the "war on drugs."

Those guidelines, which bound judges to certain mandatory minimums and automatic sentence enhancements, have been criticized for forcing judges to sentence defendants based on calculations — of the amount and type of drugs involved, and the amount of prior offenses — rather than on a case-by-case basis.

"You have a President recognizing the mistakes Congress made in the 90's, and also recognizing how hard it is to get real prison reform passed. For a President to honestly recognize that and really want to do something about it is a once in a lifetime thing," said Barrington.

Barrington's lawyers knew when they filed his petition that an immediate release was unlikely. Inmates must typically have served at least 10 years before a petition is granted. Barrington was only convicted in 2008.

Yet his lawyers believed Barrington had a strong case for clemency — even the judge who had originally sentenced him agreed that mandatory life was overly harsh. They filed his petition seeking an immediate release, but offered an alternate suggestion of a 15-year sentence — "a world of difference" from a life sentence, according to Daniel Ruzumna, one of three attorneys from the firm Patterson Bellknap Webb & Tyler who worked on Barrington's petition.

"He's always been one to admit his mistakes, and I think he recognized that some punishment was appropriate — just certainly not a life sentence. And that's thankfully what President Obama agreed with," Ruzumna told Business Insider.

Far from being disappointed or surprised at his delayed release, Barrington said he had anticipated it.

"For myself, I'm just happy to have a release date. I know how lucky I am. I have met so many guys in my situation that wish they would have taken a plea of 20 or 30 years."

An imperfect solution

Many have perceived Obama's aggressive use of clemency as a substitute for criminal justice reform from a gridlocked Congress.

Though there appeared to be a bipartisan consensus on sentencing reform earlier this year, lawmakers lost momentum in the face of the contentious presidential election. No major progress has been made.

Yet despite Obama's groundbreaking use of the executive power, the clemency program is still only a temporary, insufficient solution to the wider problem of mass incarceration in the federal system, lawyers and criminal justice experts say.

Of the approximately 211,000 people locked up in federal prisons, nearly half are imprisoned for drug offenses, according to data from the Prison Policy Initiative. Obama's 774 sentence commutations, therefore, have affected less than 1% of all federal inmates convicted of drug crimes.

And Obama is unable to grant clemency for any of the nearly 2 million inmates held in state prisons — around 200,000 of whom committed drug offenses — because that power is reserved for states' governors.

Inmates walk in at San Quentin state prison Thomson Reuters

Obama's clemency strategy has received political blowback for appearing to interfere with sentencing laws in a manner that bypasses both judges and lawmakers. In September, for instance, Congressman Bob Goodlatte (R-Va.), Chairman of the House Judiciary Committee, called on Obama to cease commuting sentences for inmates who "pose a threat to America’s public safety."

"He has effectively set himself up as a judge, reviewing thousands of cases where they’ve been prosecuted, convicted, sentenced and appealed beyond the district court level. And he's undercut all that work by commuting their sentences," Goodlatte told USA Today.

As for Trenton Copeland and his family, their only hope is that he, too, will benefit from Obama's unusual use of presidential clemency before his successor takes over.

Like Barrington, Copeland hasn't yet served a full decade on his life sentence. His attorney Brittany Byrd has sought a commutation that would leave him serving a 10-year sentence instead, which she argues is a more appropriate punishment for a non-violent crime he has expressed genuine remorse for.

Byrd said she knows Copeland wouldn't take a second chance from the president for granted.

"He is set to die in prison for a non-violent drug offense. Clemency from President Obama would literally save his life," Byrd told Business Insider. "It would mean for Trenton that his life means something."