President Obama visits the El Reno Federal Correctional Institution outside Oklahoma City in July.

When the Obama administration unveiled its clemency initiative in the spring of 2014, criminal justice advocates celebrated. After decades fighting what felt like an uphill battle over racial disparities and uneven sentencing laws, activists imagined thousands of prisoners serving incredibly long sentences for minor drug offenses finally freed.

That hasn’t happened. President Obama so far has commuted the sentences of 348 prisoners. It is more than the past seven presidents combined, but far fewer than many activists hoped and with just months left in the Obama presidency, they are pressing him to do much more while he has the authority to do so.

A coalition of more than 40 experts, former officials and activists sent Obama a letter Tuesday urging him to speed up the process and cut through bureaucracy in his administration.

“At the pace the administration has currently set, it will fall far short of granting that number of commutations before you leave office,” the letter reads. “Many of these individuals have already served decades behind bars for nonviolent drug offenses. Their families have been torn apart and their chances for happy, successful lives curtailed. Nothing can undo the injustice of their original sentences, but failing to grant the commutations for which they are eligible will add a second injustice.”

Obama has made clemency for nonviolent drug offenders a centerpiece of his goals to reform the United States’ criminal justice system.

A White House spokeswoman defended his record so far. “Through his actions and his words, President Obama has demonstrated a commitment to the commutations process not seen by any other president in the modern era,” said Brandi Hoffine in a statement. “He has written personal letters to commutations recipients.  And, he has met with those who have benefitted from commutations not just in his administration, but in past Republican and Democratic administrations, to discuss the importance of second chances.”

Hoffine also noted that, “The clemency process alone, however, will not address the vast injustices in the criminal justice system resulting from years of unduly harsh and outdated sentencing policies.  That is why we continue to support bipartisan criminal justice reform legislation.”

The coalition’s letter cites Washington Post stories on how bureaucratic tangles have bogged down Obama’s clemency initiative. And it touches on the former Pardon Attorney, who was hired to oversee the process at the Justice Department, resigning in protest over lack of resources to process thousands of applications for commutation.

Lack of resources, bureaucratic tangles have bogged down Obama’s clemency efforts

“I think there’s a level of frustration among those who know how many deserving prisoners there are,” said one of the signers, Julie Stewart. “People who served too much time already and are low risks for release.”

Stewart, founder of Families Against Mandatory Minimums, said the letter is not intended to criticize the president. “On one hand, he is the first president in decades to grant this many commutation. But on the other hand, our expectations were set high.”

And there is worry among advocates over who the next president might be and whether he or she would be as willing as Obama to make prison commutations a priority.

Nearly 12,000 commutation petitions have been filed with the Justice Department, according to the letter, and more than 1,500 are eligible for commutation under the criteria set by the Obama administration.

In a May story about the bureaucratic problems faced by Obama, The Washington Post’s Sari Horwitz talked to a Justice Department official who said fewer than 2,000 appear to be eligible for the president’s clemency program.

“At the pace the administration has currently set,” the letter warns, “it will fall far short of granting that number of commutations before you leave office.”

If Obama chose to do so, Stewart pointed out, he could grant commutations to whole classes of prisoners who received what critics say are disproportionately long sentences — such as crack cocaine and marijuana offenses.

For crack cocaine sentences, for example — which many believe targeted black offenders in past decades over white offenders who used cocaine and got lighter sentences — Congress already passed a law in 2010 lessening the mandatory minimum sentences. But the new law had no effect on offenders who had already been sentenced under the older, harsher guidelines.