Justice: For the innocent and the guilty

Two cases were before the US Supreme Court late last month concerning mandatory sentences meted out to sellers of crack cocaine.
Crack cocaine is a derivative of cocaine.  It is cheaper than powder cocaine, and it is used more by blacks and Hispanics than whites, whose drug of choice is the more expensive powder cocaine.  The penalty for selling crack cocaine is by law much harsher based on quantity. 
In the April 18th New York Times article on the subject, Adam Liptak wrote:
 “Crack and powder cocaine are two forms of the same drug.  But until recently, a drug dealer selling crack cocaine was subject to the same sentence as one selling 100 times as much powder.”
The effect was that blacks and Hispanics dispensing crack cocaine to their customers were subject to mandatory sentences of 5-10 years, whereas sellers of powder cocaine received much lower prison terms for selling the same quantity and were even released on probation for selling small amounts, for which crack sellers received prison sentences. 
In 2001 Congress—realizing the unintended racist consequences—lowered the disparity in drug weights for sentencing purposes to 18 to 1 instead of the 100 to 1 in the old law, thereby reducing the leniency provided to sellers of powder cocaine.  (Many experts believe sellers of the two forms of the drug should be treated exactly the same in sentencing.)
In the two cases before the US Supreme Court, the questions are how to sentence the defendants who committed the crime before the new law was passed but not yet sentenced, and should the sentences of those now in prison serving the harsher sentences be reduced. 
A legal problem exists with respect to making the new law apply retroactively, and that is an 1871 law.  Chief Justice John G. Roberts Jr. stated in the oral argument, that the 1871 law “required an express statement (of the Congress) if they wanted to apply the change retroactively.”  The Congress made no such statement in the new law.
There is a phrase in a religious book that I hold dear entitled “Ethics of Our Fathers” that never leaves my mind.  It is, “Justice, justice shalt thou render, sayeth the Lord.”  For me that means justice for the innocent and justice for the guilty.
It is not justice to keep people in prison longer than reasonable.  Here Congress, admitting its mistake in the past in providing prison terms that were too harsh, has an obligation, I believe, to apply the law retroactively to affect those adversely affected.  The US Supreme Court should find the 1871 law unconstitutional on the basis of lack of equal treatment required for all including those in prison.  If that happens, thousands of unreasonably punished prisoners would be liberated.  If the court does not act and leaves it to the Congress, nothing will happen.