The Nixon Presidential Library, motivated apparently by the work of its former director, has released a tape of then-California Gov. Ronald Reagan ranting about African delegates, whom he called “monkeys,” in a racist phone call to President Richard Nixon.

“To see those, those monkeys from those African countries—damn them, they’re still uncomfortable wearing shoes!” Reagan said, to laughter from Nixon.

The New York University historian and former Nixon Library director Tim Naftali published the audio recording on Tuesday in the Atlantic, where he noted that while Nixon’s racism is more well-established from other recordings, the recording provided rarer direct evidence of the 40th president’s bald racism.

The call came about in 1971, when both Reagan and Nixon were frustrated about a United Nations vote to recognize the People’s Republic of China. While the U.S. had supported recognizing Taiwan as an independent state, African delegations sided with others in supporting Chinese sovereignty over Taiwan. Naftali wrote that Nixon blamed that decision for the outcome, even though more influential European players might have more justifiably been credited with the result. When the vote came down, members of the Tanzanian delegation started dancing in celebration, apparently infuriating Reagan.

Reagan, ready to share his frustration, tried calling the president but was unable to reach him. The next morning, he called again, voicing his racist views.

According to Naftali, that call made an impact on Nixon, who repeated Reagan’s words at least twice more, with the message that “Reagan spoke for racist Americans, and they needed to be listened to.”

Here is how he described Reagan’s words in two phone calls with Secretary of State William Rogers on the same day:

As you can imagine, there’s strong feeling that we just shouldn’t, as [Reagan] said, he saw these, as he said, he saw these—these, uh, these cannibals on television last night, and he says, “Christ, they weren’t even wearing shoes, and here the United States is going to submit its fate to that,” and so forth, and so on.

And:

Reagan called me last night, and I didn’t talk to him until this morning, but he is, of course, outraged. And I found out what outraged him, and I find this is typical of a lot of people: They saw it on television and, he said, “These cannibals jumping up and down and all that.” And apparently it was a pretty grotesque picture. … He practically got sick at his stomach, and that’s why he called. And he said, “It was a terrible scene.” And that sort of thing will have an emotional effect on people … as [Reagan] said, “This bunch of people who don’t even wear shoes yet, to be kicking the United States in the teeth” … It was a terrible thing, they thought.

According to Naftali, the comments were not released with the rest of the conversation in 2000 out of a desire to protect Reagan’s privacy. Naftali, who was president of the Nixon Library from 2007 to 2011, wrote that Reagan’s death in 2004 cleared up that concern and that last year he requested the National Archives rereview the conversations involving Reagan. Two weeks ago, he wrote, the National Archives released the full versions of the conversations.

Nixon’s prejudice—from his openly racist Southern Strategy—was no secret. (Naftali notes that the tapes also record Nixon plainly discussing his belief in race science and the superiority of white and Asian populations to black and Latino ones). But most accusations of racism involving Reagan have revolved around his policies—notably, the War on Drugs—coded words possibly meant to court racist voters, or his characterization of black communities. His reliance on the “welfare queen” trope in particular evoked racist stereotypes of laziness and greed. But his defenders have been able to dispute such arguments by describing his actions and words as philosophically and policy-based rather than racist. Describing black delegates to the United Nations as “monkeys … uncomfortable wearing shoes,” however, will prove harder for those defenders to explain away.