Don Boudreaux points out that Justice Thurgood Marshall took a dim view of drug dealers and openly suggested that he would reflexively side against them in cases (via Radley Balko). Marshall told LIFE in 1987, a year after Ronald Reagan signed the 1986 Drug Abuse Act, “If it’s a dope case, I won’t even read the petition. I ain’t giving no break to no dope dealer.”
This is one of those things that really complicates Michelle Alexander's thesis that the criminal-justice system is "the new Jim Crow." It's not that she's wrong about the disproportionate impact it has on black people. It's that the junk science fueled drug panic of the 1980s and 1990s that created the draconian criminal-justice system of today included black leaders and particularly black legislators, who were concerned that the crack epidemic was going to unilaterally roll back the progress made during the civil-rights movement and destroy the black community.
Black people didn't have any role in creating the "old" Jim Crow. But black leadership was a big part of escalating the War on Drugs. Few people genuinely understood at the time that the aggregate social impact of doing so would be so devastating, and Marshall was not one of them.