Historian of civil rights movement here. The idea that the fate of poor/working class white and black people are linked and integral to any durable movement toward economic and racial justice is a core idea of the black freedom movement, and the black radical tradition broadly.

By standards of todays progressive "anti-racist" concern trolls, Hubert Harrison, Phillip Randolph, MLK, Bayard Rustin, Semptima Clarke, Ella Baker, list goes on - would have been found wanting, insufficiently woke, (clutches pearls), for "tolerating" racism, which they did not.

Condaleeza Rice enlisted the civil rights movement in service of Iraq War "democracy promotion," Obama made it about himself, HRC used it to argue against breaking up big banks, now Bernie was somehow sympathetic to segregationists. A thoroughly degraded discourse: don't buy it.

Don't doubt for minute either, if Bernie wins the nomination, the discourse will flip and it will be about how he is too concerned about black and brown people at the expense of working-class white people. (With a little he's "anti-Semitic" thrown in). And again, don't be fooled.

Running through the black radical tradition is a no less clear-eyed view of the durability and manipulability of racist division and its capacity to undermine, if not destroy radical/progressive coalitions. The error is to see this as given, rather than a changeable condition.