Over the years, too, the process appears to have been tainted by racial bias. As ProPublica documented in an analysis of Bush administration pardons, whites benefited from pardons four times as often as members of minority groups, even though blacks alone made up 38 percent of the federal prison population. That report prompted a continuing Justice Department review by its Bureau of Justice Statistics.

In addition, the department’s pardon office is run by a Bush-appointed lawyer, Ronald L. Rodgers, whose professional conduct has been excoriated by the Justice Department’s own inspector general and referred to the deputy attorney general for possible administrative action. In 2008, in transmitting a proposed pardon to the White House, Mr. Rodgers misrepresented the views of both the United States attorney who made the recommendation and the judge who seconded it. The prisoner was denied a pardon.

One simple and immediate way for the president to reinvigorate the pardons process is to choose a person of stature and energy — say, a federal judge — to steward his administration’s pardon duties. At the same time, he can end the department’s conflict of interest by replacing the pardons office with a new bipartisan commission under the White House’s aegis, giving it ample resources and real independence.

There is much good to be done, for the sake of justice as well as mercy. Many federal inmates are serving egregiously long prison terms under mandatory minimum sentencing schemes. Mr. Obama could use the pardon power to grant clemency to some long-term prisoners, until Congress reforms those laws. He could also use that power to spare some federal offenders who have completed their prison terms from the legal restrictions that have kept them from getting jobs, places to live, business licenses and the chance to vote.

And he could address the unfortunate consequences of the nation’s unfair drug sentencing laws. As of November 2011, there were at least 5,000 federal prisoners serving sentences for crack cocaine who deserved consideration for reduced sentences after a major reform of federal drug laws in 2010. Those prisoners were sentenced when the penalty for crimes involving crack was far more severe than for crimes involving powder cocaine; in 2010, Congress reduced that difference, but the older sentences remained unchanged.