In the early 1990s, journalist Dan Baum interviewed Nixon aide John Ehrlichman while doing research for a book on the effects of drug prohibition. Ehrlichman had served as a domestic policy adviser to Nixon, who in June 1971 declared a "war on drugs." After an initially fruitless discussion, Baum reports that Ehrlichman made the following confession about the real motive behind the administration's declaration of the drug war:

The Nixon campaign in 1968, and the Nixon White House after that, had two enemies: the antiwar left and black people. You understand what I’m saying? We knew we couldn’t make it illegal to be either against the war or black, but by getting the public to associate the hippies with marijuana and blacks with heroin, and then criminalizing both heavily, we could disrupt those communities. We could arrest their leaders, raid their homes, break up their meetings, and vilify them night after night on the evening news. Did we know we were lying about the drugs? Of course we did.

Baum says he chose to exclude this interview from his book because he could not find a way to neatly integrate it, and so, for nearly two decades, it remained unpublished (it made a splashless debut in an anthology of essays released in 2012).

Now the quotation appears in Harper's April cover story, and it is garnering lots of attention. While some are claiming it proves nothing less than proof positive that the war on drugs was a deliberate attack on anti-war youth and African-Americans, some former aides have publicly defended Ehrlichman, who passed away in 1999.

Three former Nixon administration officials, Jeffrey Donfeld, Jerome Jaffe, and Robert DuPont, claim that Ehrlichman's comments "reflect neither our memory of John nor the administration’s approach" to the drug crisis and were likely an example of Ehrlichman's use of "biting sarcasm to dismiss those with whom he disagreed." They also insist that "John never uttered a word or sentiment that suggested he or the President were 'anti-black.'”

This latter claim is difficult to maintain. The release of Oval Office transcripts and insider accounts of the administration over the last several decades has disclosed many racist remarks uttered by President Nixon, including his repeated use of the "n" word." Moreover, according to his chief of staff, H.R. Haldeman, Nixon said that "there has never in history been an adequate black nation and they are the only race of which this is true," and according to Ehrlichman, Nixon lamented that Great Society welfare programs were wasteful "because blacks were genetically inferior to whites."

Nixon and his aides not only harbored racist sentiments, but they also purposefully exploited post-segregation racial tensions to their political advantage. Indeed, it was Ehrlichman himself who stated that the purpose of Nixon's Southern strategy during the 1968 presidential election was to "go after the racists." Ehrlichman also observed that a “subliminal appeal to the anti-black voter was always present in Nixon’s statements and speeches."

Oval Office conversations from May 1971, one month prior to the official declaration of the war on drugs, suggest that Ehrlichman may have been accurate in characterizing the war on drugs as a veiled attempt to suppress his political enemies, including drug users.

In a taped conversation with Arthur Linkletter on May 18, 1971, Nixon – who once opined that "left-wingers" pushed drugs as a way to "destroy" American society – suddenly directed a discussion about drug abuse to the growing domestic opposition to the war in Vietnam. He referred to "radical demonstrators that were here...two weeks ago" and claimed "they're all on drugs...virtually all." Nixon then recounted how he called on Attorney General John Mitchell to "arrest the whole damn lot."

A conversation with Haldeman on May 5 reveals how Nixon considered dealing with the demonstrators who swarmed the capital that week, demanding that Congress sign a "People's Peace Treaty" to end the war. Nixon entertained the idea, first proposed by Haldeman, to use "thugs" from the Teamsters trucking union to "go in and knock their heads off." Though there is no proof that the administration orchestrated any violent backlash to the protestors, more than 10,000 demonstrators were arrested during a three-day period.

While these statements (and the subsequent Watergate scandal) suggest that Nixon was prepared to use state power to thwart his political opposition – including dissent by drug-taking anti-war protestors, some have argued that Nixon was not as cynical in prosecuting the drug war as these comments, and Ehrlichman's testimonial, imply. After all, it was Congress that passed the Comprehensive Drug Abuse Prevention and Control Act in 1970. Moreover, defenders point out, it was during Nixon's tenure that the federal government devoted more resources to treatment than to law enforcement (a policy that was discontinued beginning in the 1980s).

Yet Nixon also took steps to escalate the drug war in ways that, however unintentionally, had a "disparate impact" on demographic groups least sympathetic to the president, especially African-Americans.

In 1972, Nixon ignored recommendations issued by the Shafer Commission – established with the passage of the 1970 law – to take a more dovish approach on marijuana. This decision kept in place the classification of marijuana as a Schedule I drug. The following year, the number of arrests for marijuana increased by 128,000, and since then, 15 million people have been arrested for marijuana offenses.

The following year, Nixon also proposed a plan, unsuccessfully, to establish prison sentences for drug-related charges that included mandatory minimums and limited judicial discretion. He based his plan on changes proposed earlier that year by New York Governor Nelson Rockefeller. Reflecting on the political advantage that could come from increased incarceration, Nixon jived, "Rocky can ride this thing for all it's worth."

In the end, the public will likely never know what the true motive was behind the beginning of the war on drugs. It is certainly possible that there were mixed motives. While Nixon did express concern about the growing incidence of drug abuse both at home and abroad (particularly among soldiers in Vietnam), it seems, at the very least, that Nixon also recognized the political benefit that could come from increased legal pressure on African-Americans and rebellious youth as a result of the drug war.

What matters for the current political generation, however, is how to reform a set of drug policies that is considered widely unpopular.