On June 17, 1971, President Nixon held a press conference declaring drug abuse "public enemy number one in the United States" and asking Congress for emergency powers and additional funding to fight it. The declaration significantly expanded federal drug enforcement resources, created the Drug Enforcement Administration (DEA) in 1973, and established the framework of drug prohibition as a law enforcement rather than public health issue that has governed US policy ever since.
Ehrlichman's admission is unusual in its explicitness. But it is consistent with what the policy record shows: heroin, which was associated with Black urban communities, received mandatory minimum sentences. Marijuana, which was associated with white college students, received lighter treatment. The public health framing — drug abuse as a medical condition — was available in 1971 and was, in fact, recommended by the Shafer Commission, a bipartisan panel that Nixon himself convened. The Commission recommended decriminalizing marijuana. Nixon rejected its conclusions before it had finished its work.