Capitalism is coded to assimilate everything potentially radical and thereby render it inert. History has born out the idea that capital is not opposed to a black person or woman being president so long as they support the capitalist system and corporations. Barack Obama was swept into office in large part because he was supported by the finance industry and big banks and when the time came he was there to bail them out.
Class is the great taboo of American politics, at least as far as capital is concerned; it's of course very different when we look at different segments of the electorate. But what I think Sanders is missing here is that he's not applying the logic of that survival instinct in a rigorous and complete way. Capital will support a black president. Capital will support a female president. Capital will support everything, ultimately, even the notion of class and political revolution, because that is how capital survives. What it cannot destroy outright, it recuperates. And I think if Sanders is serious he should be watchful for the ways in which capital will try to head off and co-opt his "movement" and "revolution," whether it's the overt fascist spin on class politics of someone like Tucker Carlson or the more covert reconfiguration of capital performing "socialism" through higher wages, taxes, philanthropy, or better dental plans.