President Barack Obama is allowing the early release of 46 people jailed for nonviolent drug crimes, but reform advocates say much more needs to be done.

"Their punishments didn't fit the crime," Obama said in a video message Monday. “I’m determined to do my part wherever I can,” he said, to ensure "smarter" prison sentencing.

Advocates of sentencing reform – many excited about pending legislation that would lower some penalties – say it's important to remember many others will remain behind bars.

“We're thrilled to see that more folks serving excessively long sentences for non-violent drug offenses are going home,” said Julie Stewart, president of Families Against Mandatory Minimums. “But they're leaving behind many equally deserving people, so let’s keep these commutations coming."

The commutations take effect Nov. 10 and mostly benefit people whose convictions involve crack cocaine, the punishment for which has since been reduced. Two exclusively involve marijuana.

Obama said 14 of the people he’s granting freedom would have otherwise died behind bars.

Precise numbers are unclear, but in 2013 the American Civil Liberties Union reported at least 3,278 people were serving life without the possibility of parole for nonviolent crimes. More than 2,500 of those cases involved drug crimes.

"[T]here still remain thousands of Americans languishing in prisons serving sentences that have been repudiated by both Congress and the president," said Rep. Steve Cohen, D-Tenn., a leading supporter of drug law reform. "I hope the president continues this push for justice for all of them.”

Beth Curtis profiles 14 other people on her website LifeforPot.com who are serving life sentences for nonviolent marijuana convictions, none of whom received clemency Monday. She vetted each to ensure they had no previous convictions involving violence or other drugs.

Other sources have higher estimates for marijuana-specific life sentences. The Clemency Report says there were 54 sentences of life without parole between 1996 and 2014.

“Frankly, my belief is that there is no place for life without parole for any nonviolent drug offender,” says Curtis, whose brother John Knock is serving life in prison for a marijuana dealing conviction. “It's not fiscally responsible and the sentence doesn't fit the crime.”

Michael Collins, policy manager at the Drug Policy Alliance, echoed other reformers, saying he welcomes the new commutations, but “we need much more action."

Obama long has been characterized as stingy compared to his predecessors in exercising his constitutional pardon power. White House Press Secretary Josh Earnest pushed back on that perception Monday, saying the 46 commutations were the most in a single day “dating back to at least the Johnson administration.”

Obama ordered the early release of eight people in December and 22 people in March who were convicted of nonviolent drug offenses.

Stewart of Families Against Mandatory Minimums said clemency will remain necessary so long as mandatory minimum laws tie the hands of judges. FAMM profiles on its website prisoners sentenced under such laws, including Weldon Angelos, given 55 years for selling marijuana while owning a gun.

Like other reform supporters, activist Anthony Papa says more should be done, but he’s upbeat about what Obama did on Monday.

Anthony Papa's prison self-portrait is featured on the cover of his book "15 to Life." Courtesy of Anthony Papa

Papa was sentenced to 15 years to life in prison in the 1980s after he was arrested with about $500 worth of powder cocaine. He won clemency after 12 years in 1997, after painting a widely circulated self portrait.

Papa now works to help others facing long sentences for nonviolent offenses. Last year he posted an ad in Prison Legal News, which is circulated to inmates, asking for horror stories. And he got them. A New Yorker wrote he received 12 years for $10 worth of crack cocaine. A man in the West wrote he got 145 years for five pills.

"You read all these horror stories, it's unbelievable how the system puts away these people," says Papa, who now works at the Drug Policy Alliance.