MICHEL MARTIN, HOST:

We're going to start today with a news story that might have slipped by you given all the election news. Yesterday, President Obama commuted the prison sentences of 72 inmates who'd been convicted of nonviolent drug crimes. That move pushed to 944 the total number of people whose sentences were commuted during Mr. Obama's eight years in office. It's also the most of any president since Lyndon B. Johnson. But we're told that's not the only reason Mr. Obama's move is noteworthy.

To find out more, we sought out the person who's widely considered the authority on this subject - P.S. Ruckman, a political scientist at Northern Illinois University in DeKalb. He keeps data on presidential commutations and pardons granted since the 1700s. He writes a blog on executive commutations and pardons called "Pardon Power." And he's with us now from WBEZ in Chicago. Professor Ruckman, thanks so much for joining us.

P S RUCKMAN: Great pleasure to be with you.

MARTIN: First, can you just briefly remind us about the authority that Mr. Obama is using? And can you explain the difference between a pardon and a commutation?

RUCKMAN: The - clemency is actually the umbrella term, and pardons are one form of clemency, as well as commutations and respites and remissions and amnesties. Pardons simply remove punishment and restore rights most commonly. There can be a pardon for innocence, but that hasn't happened, oh, goodness, since the 1950s, at least at the federal level. Commutations of sentence, however, reduce the severity of the sentence. So if a person's sentenced to 20 years in prison, a commutation will reduce it to 10. Or you may reduce a fine from, you know, one level to another.

MARTIN: I just want to talk numbers just briefly here. The White House is saying that Mr. Obama has now commuted more sentences than the past 11 presidents combined. Why is that important?

RUCKMAN: Well, first, let me say I think that's outstanding. I guess, in a way, a kind of problem with that is it's like comparing yourself to the bottom quarter of your class because recent presidents have been extraordinarily neglectful with respect to the pardon power and commutations of sentence in particular. So it wouldn't be very hard or difficult, frankly, to grant more than many of them - recent presidents. President Obama's also received many more applications for commutations of sentence than several of his predecessors combined.

MARTIN: There is another difference between what President Obama is doing compared to the kinds of pardons and commutations other presidents have done previously. Could you tell us a bit more about that?

RUCKMAN: Yeah, for decades, presidents granted pardons. They simply restored rights, and they stopped commuting sentences. The other thing that President Obama's doing is he's using his power in a policy-guided way. He's identified problems in our laws, especially our outdated and now corrected sentencing laws for drugs, and he's using his commutation to address those systematic problems. And previous to him, for decades, you just didn't see any sign of that in the exercise of the pardon power.

MARTIN: About a third - a little under a third of the commutations - 324, to be exact - under President Obama's term have been people serving life sentences. Is that unusual?

RUCKMAN: Oh, absolutely. In a sense, everything he is doing is unusual, so we don't want to kind of lose sight of that. The fact that he's granted almost 1,000 of them is extraordinary. I think the only president who's commuted more sentences at present would be now Woodrow Wilson, who did, you know, a little bit over a 1,000. So President Obama's probably going to pass Woodrow Wilson, I would bet.

I think the thing that people need to really know about this is the average time served for those persons is over 16 years, and many of them are not going to be released right away. So it's important not to kind of have the perception that he's springing people from prison who have life sentences after they only served a year or two. You know, there's nothing like that going on.

MARTIN: I was going to say, before we let you go, that these decisions will not sit well with some people, particularly people who have, say, perhaps individual knowledge of individual cases, who feel like, you know, the process is the process. So for people who feel that way, what would you say to them?

RUCKMAN: Well, here's what we wouldn't want to miss. I think - I've said for many years now I think President Obama has more political capital to use the pardon power than any president in our lifetime. He granted 72 commutations of sentence four days before the election. That is freakish. And I think that just shows you that the landscape has changed, public opinion has changed. Increasingly, the left and the right are agreeing prisons are costly, they're not effective, there are other ways to do things, and that our mandatory minimum sentencing laws were faulty at best and discriminatory along the lines of race at worse. And so I believe he can probably continue to do what he's doing actually without the blowback that a president would have gotten, say, four or eight or 10 years ago.

MARTIN: That's P.S. Ruckman. He's professor of political science at Northern Illinois University and author of the blog "Pardon Power." He was kind enough to join us from WBEZ in Chicago. Professor Ruckman, thanks so much for speaking with us.

RUCKMAN: My pleasure. Transcript provided by NPR, Copyright NPR.