In a discussion on the “Fresh Air” podcast, Wilkerson said: “I think of caste as the bones and race as the skin.”

The suit comes just as six mayors ask Congress to pass legislation that would block the White House from deploying uninvited federal officers to their cities.

As global conversations about systemic racism, police brutality and the criminal justice system continue to evolve, advocates hope this holiday will finally get the recognition it deserves.

Thousands of researchers, journal publishers and university departments stopped work on June 10 to fight against “anti-black racism in the world of research.”