Barack Obama was two years old and growing up in Hawaii when Martin Luther King Jr. delivered his “I Have a Dream” speech from the steps of the Lincoln Memorial. Fifty years later, the nation’s first black president will stand as the most high-profile example of the racial progress King espoused, delivering remarks Wednesday at a nationwide commemoration of the 1963 demonstration for jobs, economic justice and racial equality. Obama believes his success in attaining the nation’s highest political office is a testament to the dedication of King and others, and that he would not be the current Oval Office...