“Kamala Harris is *not* an American Black. She is half Indian and half Jamaican,” read one of a dozen similar tweets questioning Harris’ identity sent in the moments after she, while confronting Joe Biden’s record of opposing desegregation, recalled being bused to school as a little girl. Another read, “KAMALA HARRIS IS NOT BLACK” and featured a photo of Harris with a “Kamala Dolezal” emblazoned across her face, referencing Rachel Dolezal, a white woman who claims to be “transracially” black. Yet another read, “Kamala Harris is implying she is descended from American Black Slaves. She’s not. She comes from Jamaican Slave Owners. That’s fine. She’s not an American Black. Period.” That last one, written by black right-wing provocateur Ali Alexander, was retweeted by none other than Donald Trump Jr., along with a question: “Is this true? Wow.”

By the end of the night, Trump Jr.’s tweet had been deleted. But it was too late: The message of a fringe movement had been elevated to his millions of followers and, at least briefly, gone mainstream. The moment was months, or even years, in the making.

At first glance, the tweets questioning Harris’ black bona fides look apiece with the racist birther conspiracies levied against Barack Obama when he ran for president—the tweets are an effort to paint her as an imposter (and indeed, there’s evidence the “Kamala Dolezal” memes originated in the same toxic spheres as the birther movement). But a quick look at the bios and tweets of the people who have most vocally and consistently questioned Harris’ blackness, and her ability to speak to the experience of black Americans, most frequently feature not the #MAGA hashtag, but another one: #ADOS, or American descendants of slaves.

According to one theory, accounts that use #ADOS are a sinister collection of Russian bots and trolls sowing misinformation and apathy toward Democratic candidates in the runup to the 2020 election. Or they’re a façade for nativist white supremacists who are trying to drive a wedge between American black descendants of slaves and black immigrants. Or, maybe, they’re a real, vocal group of black critics silenced by moderate liberals who refuse to brook any criticism of candidates like Harris. Whatever the case, they’ve attracted powerful black opponents like rapper Talib Kweli, actress Yvette Nicole Brown, and MSNBC host Joy Ann Reid, who in a segment on her show had a guest suggest that the ADOS hashtag is a way to spot Russian trolls masquerading as black people.

The real story of #ADOS is, unsurprisingly, more complicated than any of these parties want to acknowledge. The ADOS hashtag was created by attorney Antonio Moore and political commentator Yvette Carnell. Neither of them is a bot, or a Russian. In interviews with the Intercept in the aftermath of the Democratic debate that brought the hashtag to the fore, Moore and Carnell both dismiss criticism like Reid’s as an effort to “undermine authentic Black advocacy in order to prop up the Democratic establishment.” They describe the goals of #ADOS as “agenda politics” rather than identity politics, calling on Democratic candidates to support a “New Deal for Black America,” a set of specific policies designed to address the institutional and systemic plunder that has defined America’s relationship with blackness since its founding. The ADOS policy page details the specific measures the group supports, including reparations for the descendants of people held in chattel slavery, government subsidies for health care and education, and affirmative action for slave descendants.

The ADOS movement, such as it is, is one of many forums in a larger conversation that questions black homogeneity in America. That conversation will only grow louder as the issue of reparations—and who deserves them—continues to gain momentum following a congressional hearing on the subject last month.

But a closer look suggests ADOS is hiding a blackness purity test in rhetoric about who deserves those reparations. As Michael Scherer and Amy B Wang put it in the Washington Post on Monday, “The underlying message is that black Americans from immigrant families, even places like Jamaica, with a history of slavery under Spanish and British rule, do not have the same claim to the identity or the struggle for civil rights.” And there’s troubling evidence that anti-immigrant bias is at the heart of that message.

There’s troubling evidence of anti-immigrant bias at the heart of the message.

On the ADOS policy page, the group stipulates that the census should introduce a new designation for “ADOS and another for Black immigrants. Black immigrants should be barred from accessing affirmative action and other set asides intended for ADOS, as should Asians, Latinos, white women, and other ‘minority’ groups.” According to the same Washington Post report, Carnell, the co-founder, was previously on the board of Progressives for Immigration Reform, which, despite its name, has deep ties to the anti-immigrant right. Moore, for his part, wrote a 2016 HuffPost op-ed arguing that Trump’s hard-line stance on immigration is warranted because undocumented immigrants are to blame for black unemployment. He also likes to suggest that critics of the movement like Reid aren’t qualified to comment on it because they are children of immigrants.

Moore, Carnell, and their followers also tend to reserve their harshest criticism for prominent liberals, attacking figures like Ta-Nehisi Coates for supporting a public study about what reparations would look like. (They argue it’s a “cop out” because it would seek to study reparations before dispersing them.) Accounts using the ADOS hashtag have suggested punishing Democrats for not endorsing a reparations program by not voting, or voting for Trump, in 2020 (though Moore and Carnell say they reject this). ADOS organizers claim they don’t press conservatives for support for reparations because the left has too long “expected us to be the mules of the Democratic Party.” Rhetoric like that has gained the attention—and support—of several right-wing activists, including Ann Coulter, who tweeted, “I like #ADOS,” and suggested a name change to DOAS, for Descendants of American Slaves.

Beyond ADOS’s more fundamental issues, experts have also raised the alarm at how easily it could be hijacked for other purposes. Malcolm Nance, a counterterrorism and intelligence consultant for the U.S. government, warned on Twitter that “For 5 months a small group of black cyber security experts have been watching a bunch of black Trumpers using #ADOS & warning it was the leading edge of a racist Russian cyber attack on @KamalaHarris. Many bots. Some trolls.” Indeed, there’s evidence purveyors of misinformation are more than happy to use #ADOS as a weapon in their meme arsenal. On a 4chan /pol/ thread that asks for dirt on Harris, one user wrote, “Highlight the fact that most Americans blacks (#ADOS) hate her from posing as one of them, when in fact she’s a descendant of Caribbean slave owners and high-class street-shitters. She does not speak for African Americans.” Another wrote, “I have a bunch of Tw@tter accounts for the sole purpose of astroturfing reparations. It will splinter the Democrat Party. #ADOS #FuckYouPayMe.” Yet another said in January, “Make sure we let them know Kamala is Jamaican/Indian mix and she’s not an ADOS American descendant of slaves.”

ADOS’s relatively small size only makes it more difficult to separate real rank-and-file followers from trolls capitalizing on racial divisions to hurt Democrats. Twitter said it saw “no coordinated use of automation” during or after the debate, but that doesn’t rule out bad actors, and some of the accounts that questioned Harris’ blackness are now suspended. Still, many others are operated by real people, who, in the pursuit of reparative justice for slave descendants, are willing to gloss over or embrace anti-immigrant rhetoric. It’s hard to say if this grassroots movement is gaining real steam, but it’s clear that right-wing political players believe they have the most to gain from it.