I think that one of the best Martin Luther King day tributes came from Jon Rosenberg, creator of Scenes from a Multiverse. The premise of the comic is that there are an infinite number of universes inhabited by sentient beings, all of whom are pretty much exactly as fucking stupid as we are.
MLK was assassinated during a push for worker's rights, part of a social justice initiative that went beyond the call for de jure equality and made the case for a more equal society. In today's America, Martin Luther King's name is one embraced by people of all backgrounds, creeds, and political persuasions. But if you share his goals, you get beaten in the streets just the same as his followers did at the time.
Many, on air and off, have asked the question: "What would Martin Luther King Jr. say if he saw today's America." Obviously none of us know, but whatever it is, it would without a doubt be painful to hear.