“The descendants of slaves certainly deserve the same considerations,” said JoAnn Watson, a former Conyers aide who later spent a decade as a Detroit city councilwoman. “The time for reparations has come.”

Darity’s efforts will probably be both furthered and complicated by his public association with a small but outspoken online movement called American Descendants of Slavery, or ADOS, which draws a stark distinction between the lineage of slave descendants and that of American-born descendants of black immigrants.

The group, like Darity, advocates that reparations be strictly reserved for those who can trace their lineage to enslaved people held in the United States, excluding the children of more-recent African and Caribbean immigrants who have also been subject to race-based discrimination. More divisively, the group and its leaders also have aggressively argued that current immigration levels present a threat to the livelihood of black Americans.

That framing has rankled many black activists — some of whom have documented being harassed online by ADOS supporters — who have long adopted a more Pan-African ideology and see any effort to delineate among various groups of black Americans as having the potential to fuel xenophobia. In interviews, half a dozen activists and academics praised Darity’s work but found themselves perplexed by his willingness to associate with ADOS.