Both the GOP and Democrats have grossly distorted the message of MLK Jr, but especially the GOP. MLK Jr. preached and advocated for social and economic equality. The socialist message of MLK has been largely ignored by Democrats and has been totally ignored by Republicans. The GOP has gone further to distort even the message of social equality.
Martin Luther King was an activist for justice, not simply a speaker who said pretty words. Many modern day conservatives seem to forget that he used civil disobedience to achieve his goals, and he was insistent that the concerns of minorities be taken seriously regardless of how uncomfortable that made people. If he were alive today, I believe the GOP would be critical of him, given their behavior towards current social activists.
Liberals love to pat themselves on the back for improving race relations, yet after 8 years of a democrat in the oval office, we're still stuck with the drug war, which is the most racist policy we have in America. Sure, the GOP is terrible for civil rights, but the left is fighting the wrong battles. It's no great thing to be barely better than the other guy.
Martin Luther King, Jr. was an honorable man and history will remember him as such, no matter what any political party may do. Our public schools teach our children every year, around his birthday, about the great gains he made to further the Civil Rights Movement, and he continues to influence generation after generation by the examples he set utilizing peaceful demonstrations.