I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character.
Judging people by their character is what Republicans stand for. Judging people by their skin color is precisely what the Democrats want to perpetuate.
You're absolutely right. And although King did push for greater attention and aid to the plight of the poor, see, e.g., http://en.wikipedia.org/wiki/Poor_People%27s_Campaign , he did so utterly without regard to race, even campaigning in areas where virtually all "the poor" were white.
Interesting that Dean conveniently edits history to reflect only what he wishes it to.