ADVANCE FOR USE MONDAY, JAN. 21, 2013 AND THEREAFTER - FILE - In this Aug. 28, 1963 file photo, the Rev. Dr. Martin Luther King Jr., head of the Southern Christian Leadership Conference, speaks to thousands during his "I Have a Dream" speech in front of the Lincoln Memorial for the March on Washington for Jobs and Freedom in Washington. Actor-singer Sammy Davis Jr. is at bottom right. It has been cited as one of America's essential ideals, its language suggestive of a constitutional amendment on equality: People should "not be judged but he color of their skin but by the content of their character." Yet 50 years after the King's monumental statement, there is considerable disagreement over what this quote means when it comes to affirmative action and other measures aimed at helping the disadvantaged. (AP Photo)