From a good old article by Lew Rockwell:
The received wisdom on the Right these days is that King would have rejected the excesses of the modern civil rights movement. But that clearly isn’t the case. Indeed, David Garrow in his Pulitzer Prize-winning biography says that in private gatherings King endorsed “democratic socialism,” while making “it clear to close friends that economically speaking he considered himself what he termed a Marxist.”
So while the rest of the country accords to King a level of veneration perhaps matched only by that they’re showing to Obama, its important to remember that he was a central planner and an enemy of a libertarian society just like the rest of our modern heroes. He was perhaps a well-intentioned one, but then again the road to hell is paved with good intentions.