I'm sympathetic to Richard Beck's argument, but he makes a major error of fact in On White Privilege. You can't trace Derrick Bell to Marx. Bell said late in his life, “I think there must be value in Marxist and other writings, but I did not really read them in college and have had little time since.”
Though perhaps Beck only means that some of Critical Race Theory has been shaped by people who knew a little about Marx. I don't know enough to respond to Beck's "if I were a Marxist, I would accuse the Radical Race Theorists of misappropriating the Hegelian Dialectic." Ideologues appropriate, so there could be something in that notion for someone else to explore. But since Beck's not a Marxist, I wouldn't put too much weight on it.