About 500 people attended a \"mobilization rally\" Saturday to organize and plan how they can halt threats to voting and civil rights, particularly a referendum issue in Michigan that could end affirmative action in the state. Speaking at the rally in the Northwest Activity Center in Detroit were activist Dick Gregory; Sharon McPhail, general counsel to the Detroit mayor; Frank Wu, dean of the Wayne State University Law School; and Mary Francis Berry, former chair of the U.S. Civil Rights Commission.