As a US attorney, the new acting head of the US Drug Enforcement Administration enthusiastically enforced drug sentencing laws that contributed to racial disparities in the criminal justice system and the war on drugs.

US Attorney General Loretta Lynch on Wednesday named Chuck Rosenberg, the FBI director's chief of staff, to replace current DEA Chief Michele Leonhart, USA Today's Kevin Johnson reported. Leonhart is resigning following allegations that DEA agents in Colombia took part in sex parties funded in part by drug cartels.

Leonhart has been a stark critic of drug policy reforms, previously saying she supports mandatory minimum sentences that the Obama administration disavowed. Drug policy reformers were hoping her replacement would be friendlier to reform.

But as US attorney for the Eastern District of Virginia, Rosenberg unapologetically enforced mandatory minimum sentences for crack cocaine that contributed to the wide sentencing disparities between black and white Americans, as Emma Schwartz reported for US News:

In 2006, the Eastern District of Virginia topped the nation in crack cocaine prosecutions with 253 — a sign that crack dealers will continue to face heavy enforcement in the region. And Chuck Rosenberg, U.S. Attorney for the Eastern District of Virginia has no regrets. "It's a federal crime, so I don't apologize for prosecuting it."

Harsh crack cocaine sentences were established in the 1980s as part of the US's escalation of the drug war. The Obama administration signed the Fair Sentencing Act of 2010 to tame the sentences, but only after decades of police and prosecutors carrying them out in a way that hit minority communities the hardest.

The crack cocaine sentences have been criticized as racist

In the US, someone would need to possess 18 times the amount of powder cocaine as crack to get the same mandatory minimum sentence — even though both drugs are pharmacologically identical and produce similar effects.

The sentencing disparity between crack and powder cocaine used to be worse, but in 2010 federal lawmakers reduced it from 100-to-1 to 18-to-1.

The crack sentences have been widely criticized by drug policy reformers as racist. Although crack and powder cocaine are pharmacologically similar, crack is cheaper, making it more accessible and often the preferred version of cocaine in poor, black communities.

As a result, black Americans have been disproportionately arrested and charged for crack offenses. About 83 percent of crack trafficking offenders in fiscal year 2013 were black, 10 percent were Hispanic, and 5.8 percent were white, according to the US Sentencing Commission (USSC). In comparison, 58 percent of powder cocaine trafficking offenders were Hispanic, 31.5 percent were black, and 9.4 percent were white, according to USSC.

Since crack carried a considerably harsher penalty, USSC found more than 67 percent of crack offenders in 2013 were sentenced to five or more years in prison, compared with 56 percent of powder cocaine offenders. And this is after the Fair Sentencing Act passed and reduced the sentencing disparities between both substances.

The uneven sentencing is one of the reasons black Americans are much likelier to be arrested and imprisoned for drugs than their white counterparts, even though both groups use and sell drugs at similar rates.

(h/t Bryce Pardo.)