"The difference is that they did not have the kind of support structures, the second chances, the resources that would allow them to survive those mistakes."
The frank assessment - which the President made before a group of journalists - came just two days after he told a largely black audience that "I see what happens" when black and Latino families are devastated by the high rates of incarceration in their communities.
And yesterday, during a White House news conference, Obama said that while the criminal justice system is not "the sole source of racial tension in this country, or the key institution to resolving the opportunity gap", he sees reforming it as a way to help deliver on the nation's promise of treating its citizens equally, without regard to race.
For a President who has often been reserved when discussing hot-button racial issues, Obama has begun to make a moral case based on his own identity.
"This is a moment when the President, speaking very candidly about the number of black men behind bars, is able to really talk about this issue in race-specific terms, and in a race-transcendent way," said NAACP president Cornell William Brooks, whose group Obama addressed on Thursday in Philadelphia. Obama has framed the overhaul of the national criminal justice system as an issue of both fairness and common sense; by saving taxpayers' money while also keeping some offenders from becoming hardened criminals.
"We have to consider whether this is the smartest way for us to both control crime and rehabilitate individuals," Obama said. "We have to reconsider whether 20-year, 30-year, life sentences for non-violent crimes is the best way for us to solve these problems."
Elected officials from both parties, as well as the President, have proposed revising the strict federal sentencing guidelines for non-violent drug offenders put in place during the crack epidemic of the 1980s.
On Wednesday the President commuted the sentences of 46 men and women convicted under those sentencing guidelines. Last year the Justice Department set criteria for granting clemency to such offenders; about 17 per cent of the prison population has applied.
As part of the White House push to draw attention to the issue, Obama toured a facility in the flat prairie about 50km west of Oklahoma City, where visitors must walk through numerous gates and past fences with barbed wire.
The President walked down two long rows of cells, looking inside one that had two beds, a sink and toilet in the corner. The prison is overcrowded, he said, squeezing three inmates into a 9 by 10 cell.
Before speaking to reporters Obama participated in a roundtable with the six inmates as part of a special the network VICE is producing on the United States criminal justice system.
"For people who look at the President and can see themselves reflected in some part of him, having him acknowledge their existence and the hardship they face is extremely significant," said Teresa Miller, a law professor at the University at Buffalo.
While the federal prison system has an overcrowding rate of 137 per cent in 2013, the average rate for maximum security facilities is at 154 per cent. In May, rioting at an overcrowded Nebraska prison caused multiple fatalities.
"It's an extreme level of overcrowding that is a recipe for disaster," Fathi said.