169011
Finding that blacks have always made up a substantial majority of the county 's population but that they are a minority of the registered voters , that there had been bloc voting along racial lines , and that past discrimination had restricted the present opportunity of blacks to participate effectively in the political process , the District Court held that although the state policy behind the at-large electoral system was " neutral in origin , " the policy was being maintained for invidious purposes in violation of appellees ' Fourteenth and Fifteenth Amendment rights .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None