Sad you didn't start with the history of these sentences. Your column implies racism.  Wrong! The sentences were an attempt to stop crack from spreading in the Black community.  You don't mention higher Meth sentences that exist for the same reason but affect whites and Hispanics.  Why not?  Don't you want justice for all?

The Congressional Record shows in 1986, when the strict, federal anti-crack legislation was first being debated, the Congressional Black Caucus (CBC)deeply concerned about the degree to which crack was decimating black communities across the United States—strongly supported the legislation and actually pressed for even harsher penalties. A few years earlier, CBC members pushed Pres. Reagan to create the Office of National Drug Control Policy.

It should  be noted that the vast majority of cocaine arrests in the U.S. are made at the state-not the federal—level, where sentencing disparities between cases involving crack and powder cocaine generally have never existed.