Since 1986, criminal defense lawyers and academics have argued that the federal sentencing guidelines for crack cocaine, compared with those for powder, were unfair and inherently racist, and now a federal commission has taken a first step at reforming them.

The U.S. Sentencing Commission has issued amended guidelines, effective this Nov. 1, that will reduce the average sentence of crack users by 27 months, but will do little to reduce the up to 100-to-1 disparity between crack and powder cocaine sentences.

But those guidelines don't say whether the sentence reduction should be made retroactive, making thousands of inmates eligible for release. The commission held hearings on that matter last week.

The Nov. 1 action of the commission, which has issued four reports to Congress over the years calling for cocaine sentencing reform, will have a very modest effect on the radical disparity between crack and powder. A person caught with 5 grams of crack cocaine -- equal to 10 to 50 doses -- would still receive the same five-year mandatory minimum sentence in federal court as a person caught with 500 grams of powder -- equal to 2,500 to 5,000 doses.

People caught with higher quantities would fare better under the new guidelines, which would slightly lower the disparity in the crack vs. powder sentences at that level. A person caught with 20 to 35 grams of crack, who previously would have been sentenced to 78 to 97 months, would now be sentenced to 63 to 78 months.

Though legislation is currently pending that would equalize penalties for powder and crack cocaine, the effect of the small-scale guideline changes makes clear the scale of a complete equalization. Should the commission make its changes retroactive, nearly 20,000 currently incarcerated federal inmates across the country would be eligible for early release over the next several years.

Opponents argue that releasing that many inmates early will place an undue burden on the criminal justice system, and also put communities at risk because serious, often violent criminals, will be re-entering their neighborhoods.

Advocates for retroactivity say it is only fair to correct the injustice that's been brought upon those already incarcerated. Further, they argue that the burden on the system would be spread out across 93 U.S. District Courts over a period of many years.

In the Western District of Pennsylvania, according to the sentencing commission's study, a total of just 126 offenders would be eligible for the reduction.

Add in the entire state of Pennsylvania, and the number jumps to 772.

Alfred Blumstein, a criminologist at Carnegie Mellon University, has studied the disparity between crack and powder cocaine and testified on the issue.

When Congress passed the laws dictating sentences for the two drugs, Mr. Blumstein said, legislators were trying to address the violence associated with crack cocaine.

What happened, though, is that they made the penalties for that drug, which was more prevalent among African Americans, much more strict even though the two drugs have similar effects.

"The difference was intended to respond to the violence," he said.

But what should have happened, he said, is that the sentencing guidelines would have set equal limits for both types of drug and add increased penalties to address any violence associated with the offender's behavior.

After the sentencing commission announced the new guidelines, it requested public comment on retroactivity.

It received more than 33,000 letters.

Among them was a 12-page letter from Assistant Attorney General Alice Fisher.

Writing for the U.S. Department of Justice, Ms. Fisher said that making the guidelines retroactive would create years of substantial litigation, uncertainty for finality of sentences in tens of thousands of cases and "undermine the public's faith in the judicial system."

It would also negatively impact the government's ability to prosecute current offenses.

Further, she wrote that it would introduce "widespread and unjustified disparity among defendants and unjustifiably overburden the limited resources of the federal judicial system, including judges, probation officers, prosecutors and defenders."

Local defense attorneys bristled at the Department of Justice argument that retroactivity would be a burden on the system.

"That is the most obscene argument," said Thomas J. Farrell, who used to work as an assistant U.S. attorney. "Society has made a determination we over-punished these people.

"You're not supposed to punish people gratuitously."

Mr. Farrell recognizes that there could be some difficulty in transitioning offenders back into the community more quickly.

But in the next breath, he adds, "Within 27 months, these people would be out anyway."

Paul Boas, who could think of one client who would have received a 10-year sentence instead of 11¹/₂ under the new guidelines, said that the sentence reduction is an acknowledgement that the system has been unfair.

"The only real reason not to do it is there's a lot of paperwork and a lot of bureaucratic hassle," Mr. Boas said. "And that's no reason."

Ms. Fisher also wrote that early release poses a danger to the community, since crack dealers are often violent.

"Crack trafficking crimes are not victimless crimes," she wrote. "The entire neighborhood suffers because of the way in which crack is distributed in open markets."

But Mr. Blumstein said that every time any inmate is released there's an increased possibility of crime.

"There's no reason to believe these people are more likely to engage in crime than anyone else being released," he said.

As of last week, federal prisons held a total population of 200,326 inmates. In 2004, approximately 46,000 inmates were released.

That makes the release of some 19,000 inmates spread out over several years more manageable, Mr. Blumstein said.

"I suspect the peak of 6,000 [in a single year] is not going to be a dramatic increase," he said.

Gary Zimmerman, a criminal defense attorney in Pittsburgh, has argued against the disparity between crack and powder cocaine sentences three times before the 3rd U.S. Circuit Court of Appeals.

He believes the change in the guidelines should be retroactive.

"I think all these kids in jail on these long crack cocaine sentences should be offered some relief, out of fairness for one, and to ease the burden on the prison system," Mr. Zimmerman said.

He called the Department of Justice argument "absurd."

"Right now, it's a burden on the taxpayers having to keep them in jail," he said.

It costs an average of $24,440 to house a federal inmate each year.

Marc Mauer, the executive director of the Sentencing Project, said that if 19,000 inmates got an average of two years less in prison, that would result in a savings of $1 billion in prison housing costs.

"It would far outweigh any costs they would have up front on the courts," he said.

Mr. Mauer also noted that federal judges, represented at the sentencing commission's hearing last week by the Committee on Criminal Law of the Judicial Conference of the United States, said that they did not think retroactivity would be a problem.

"It's absolutely up to the judge," Mr. Mauer said. "Nobody has an absolute right to be free. The judge retains final discretion over this."

He also noted that changes in sentencing guidelines in the 1990s for both marijuana and LSD -- which primarily benefitted white offenders -- were made retroactive.

"If they do not make [the crack guidelines] retroactive, it would be very striking," Mr. Mauer said.

He acknowledges that the current guidelines change is modest, compared with the 100-to-1 disparity in federal court today between possession of crack and powder cocaine.

But, he added, that can only be addressed by Congress, which he thinks is likely to happen soon.

"The momentum's coming from a lot of different directions," he said. "There's much greater interest than we've had in 21 years."