I'm sure he would be distressed by the level of deliberate and strenuous efforts to ratchet up racial animosity that are prevalent among certain classes of people now. At least I hope he would.
The shocking thing, the thing which I at any rate certainly did not anticipate in the '60s when the major civil rights legislation was passed, is that the most visible manifestation of this effort now comes from the putatively anti-racist side, in the form of the frenzied rhetorical attacks on white people and "whiteness" coming from the left. Much of it is is open and unashamed racism and would be recognized immediately as such if the terms were reversed. The most alarming aspect of it is that it isn't the work of obscure and generally disdained cranks and yahoos but of respected academics and journalists who wield a great deal of influence. Respected by each other, anyway. And in any case fairly powerful.
King's ideal of a color-blind society is now considered to be an expression of racism, at least if advocated by white people. It wasn't supposed to be like this.
So much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot.
Sow the wind, reap the whirlwind.