The previously obscure far-left term became common currency in the lexicon of the conservative social and political challenges against progressive teaching methods and curriculum changes in the secondary schools and universities of the U.S. Policies, behavior, and speech codes that the speaker or the writer regarded as being the imposition of a liberal orthodoxy, were described and criticized as "politically correct". In May 1991, at a commencement ceremony for a graduating class of the University of Michigan, then U.S. President George H. W. Bush used the term in his speech: "The notion of political correctness has ignited controversy across the land. And although the movement arises from the laudable desire to sweep away the debris of racism and sexism and hatred, it replaces old prejudice with new ones. It declares certain topics off-limits, certain expression off-limits, even certain gestures off-limits."