UnlessCongress acts quickly, on March 3 thousands of convicted felons will be allowed to petition federal judges to get out of jail early.

The U.S. Sentencing Commission recently issued new guidelines that make retroactive revised sentences for crack-cocaine possession. But all stakeholders in the criminal justice system -- defendants, prosecutors, defense counsel, the police, probation officers, judges and, most importantly, the public, deserve better.

Congress should move swiftly to reject the guidelines that would give duly convicted recidivists and violent felons a "Get Out of Jail Free" card and allow them to re-litigate their sentences.

Let's not forget why those sentences were harsh. By 1986, cheap crack-cocaine infested American inner-cities, bringing epidemic levels of violence. Congress passed tough sentencing laws to curb the threat.

The Commission adopted Congress' 100-to-1 crack-to-powder ratio as the basis for its 1987 guidelines on penalties relating to crack. Defendants caught with five grams of crack faced a five-year mandatory minimum sentence, and those with 50 grams, a 10-year sentence.

Those caught with powder cocaine received substantially lower sentences. The tough penalties for crack won wide support, and Congress and the courts repeatedly have affirmed that get-tough policy.

Yet opinions on the crack/powder sentencing disparity changed over time. The epidemic gradually waned in response to innovative policing strategies and, in part, to the tough mandatory sentences.

In April 2007, the Commission lowered the sentencing guidelines for crack. Because Congress didn't act to overturn the revised guidelines, they became law last November.

What's at issue now, however, is how that change should apply to those convicted before the new guidelines came into effect. The Commission also made the lower sentences retroactive, effective March 3.

Earlier this month, Attorney General Michael Mukasey asked Congress to pass legislation barring retroactivity for most of those convicted under the old guidelines, warning that failure to act would make 1,600 convicted crack dealers eligible for immediate release and could lead to decreased sentences for more than 20,000 crack dealers overall.

Critics accused him of trying to "scare" Congress into acting and that his alarm was "unwarranted." They note that any sentence reductions would have to be approved by a federal court, which will ensure that convicts who represent a danger to public safety don't get out early.

The issue, however, is not whether we trust judges to follow the law and exercise their considered discretion, but what the policy should be in the first place.

Public safety isn't the only ground for concern about wholesale retroactivity. Justice and fairness complicate things.

As for justice, it is not enough to focus on the hyper-technical details of the sentencing guidelines without considering how prosecutors do their jobs and how retroactivity will throw a wrench into the system.

Prosecutors exercise great discretion in developing their cases. Before they even begin an investigation, they know which crimes are "easy" to prove, which crimes take more time and resources to prepare for trial and what sentences are associated with each crime.

Proving a possession of crack-cocaine case is relatively easy. Thus, when choosing how to prosecute a defendant involved in a case involving drugs, guns and other violence, the government often takes the path of least resistance; sometimes that means prosecuting the drug charge and not developing the gun or violent crime aspects of the case.

Prosecutors make deals with defendants because it serves fairness and prosecutorial economy. Over 90 percent of criminal cases are resolved by plea bargain. Defendants who plead guilty do so in exchange for the prosecution dropping other charges.

This complicates things. For example, a prisoner who received a 10-year sentence for dealing crack but wasn't charged with a weapons offense due to prosecutorial discretion may get a few years knocked off of his sentence, while a prisoner with a 10-year sentence for the same weapons offense alone gets nothing. That isn't justice.

As for fairness, there is a strong argument that first-time and non-violent crack offenders got a raw deal under the old sentencing scheme. As a matter of public policy, Congress should allow the reduced sentencing guidelines to be retroactively applied to them.

On the other hand, what could be fairer than a recidivist or violent felon receiving a crack sentence in accordance with the law at the time of trial?

It's not unfair for a career criminal who broke the law to get the punishment he knew was coming. In the interests of all concerned, Congress should refuse to give career criminals the privilege of another sentencing hearing.

Cully Stimson, a former prosecutor and defense attorney, is a senior legal fellow.