I have a speculation, an hypothesis. I stress that because I have not data to support it, and I'm not sure how one would even acquire such.
I have commented often that standard-issue elite liberals socially enforce tribal discipline with condescension. It is a warning that one might next be socially excluded. I likely have given the impression that this condescension is always delivered with a sneer, whether orally or in print. Much of it is, but that is not universal. There are earnest, wide-eyed liberal folks who don't necessarily mean to condescend, and have no trace of it in their tone. They are just commenting, with general bonhommy (reference?) about how the general mass of humanity needs to be educated about their particular cause, and we need to raise awareness about this or that. They are not aware of any especial contempt for the great unwashed, they just don't know, not like thier good friends who have read the right books.
So just keep that piece in mind when I suggest the following.
Who would be most vulnerable to being affected by such condescension, whether said meanly or earnestly? The vague discomfort of sensing a world of the intelligent, good people almost in reach - but one you could be turned away from as not quite good enough? Young people, certainly, but also any outgroup, especially minorities. The Jews have developed an American strategy of "we'll beat you at your own game," and in many ways taken over many of the wittier, more cosmopolitan high spots. Not only do we get it, we get it better than you. We can grab these spots and set the rules.
I would think African-Americans, especially bright and educated ones who hover at the brink of acceptance into the elitest - most righteous, most thoughtful - would be highly susceptible to the promised charms of entry into the inner circle.
Perhaps I am projecting. I was a bright child of divorced parents in an era when divorce was not mentioned aloud, who always felt I had something to prove, and for whom entrace into an inner circle could be very sweet. I was vulnerable and susceptible, and perhaps I assume too much about others. But it intrigues me.
It is much easier for me to shrug off the condescension of liberals because I proved I could do it. I don't have any fears that I wasn't clever enough or socially aware of subtle cues that progressives identify each other with. I did it, and I have to tell you it's not that hard to be a liberal. It is far more socially demanding, sensing the room and knowing where to get reinforcement for your sense of superiority, than it is intellectually demanding.