I DOUBT any president has been as well equipped as Barack Obama to appreciate the vicious cycle of American crime and punishment. As a community organizer in Chicago in the 1980s, he would have witnessed the way a system intended to protect the public siphoned off young black men, gave them an advanced education in brutality, and then returned them to the streets unqualified for — and too often, given the barriers to employment faced by those who have done time, disqualified from — anything but a life of more crime. He would have understood that the suffering of victims and the debasing of offenders were often two sides of the same coin.

It’s hard to tell how deeply he actually absorbed this knowledge. In the Chicago chapters of his memoir, “Dreams From My Father,” Obama notes that in the low-income housing projects “prison records had been passed down from father to son for more than a generation,” but he has surprisingly little to say about the shadow cast by prisons on the families left behind, about the way incarceration became the default therapy for drug addicts and the mentally ill, about the abject failure of rehabilitation.

Still, when the former community organizer took office, advocates of reform had high expectations.

In March I will give up the glorious platform of The Times to help launch something new: a nonprofit journalistic venture called The Marshall Project (after Thurgood Marshall, the great courtroom champion of civil rights) and devoted to the vast and urgent subject of our broken criminal justice system. It seems fitting that my parting column should address the question of how this president has lived up to those high expectations so far.

I’ll begin by making his excuses. The president’s powers in this area are limited. The action (and there is a lot of it right now) is mostly at the state level. His first term was entangled in economic crisis and health care. This president has faced tireless and often petty resistance from the Republican House on almost every initiative. Historically Democrats have risked being Willie-Horton’ed if they don’t maintain a tougher-than-tough-on-crime posture. And African-American constituents — who are also disproportionately the victims of crime — are not necessarily bleeding-heart voters. In short, it was probably naïve to assume that Obama was going to be the Criminal Justice Reform President.