1980 April 23 In an unprecedented decision , the Supreme Court votes 6 to 3 that intentional discrimination must be proven to declare a local election system unconstitutional. Mobile, Alabama's, at-large voting system was found constitutional, overturning the rulings of two lower courts. Not one black had been elected city commissioner or to the county school board in the city 's history, although blacks comprise 35.4% of its population. Justices William Brennan, Byron White, and Thurgood Marshall wrote dissenting opinions.