defiance of constitutional authority. Otherwise, 'it amounted to no more than a protest, an escape valve through which the legislators blew off steam to relieve their tensions.' ... However solemn or spirited, interposition resolutions have no legal efficacy." Interposition and nullification were referenced by Dr. Martin Luther King Jr. in his August 1963 "I Have a Dream" speech, at the March on Washington for Jobs and Freedom: I have a dream that one day down in Alabama with its vicious racists, with its governor having his lips dripping with the words of interposition and nullification, one day right there in Alabama little black boys and black girls will be able to join hands with little white boys and white girls as sisters and brothers. Contemporary debate Interposition and nullification have been raised recently in several state legislatures. Some legislators argue that the states should use these theories to declare unconstitutional certain acts of Congress, especially including the Patient Protection and Affordable Care Act of 2010. Interposition or nullification bills have been introduced in several state legislatures. Opponents respond that interposition is not a valid constitutional doctrine and has been discredited. See also Sherman Booth, an example interposition from Wisconsin Lesser magistrate References External links Copy and transcript of Florida's Interposition Resolution in 1957; made available for public use by the State Archives of Florida Political history of the United States Nullification (U.S. Constitution) John C. Calhoun