¹ Matthews, Donald R. and Prothro, James W., Negroes and New Southern Politics (New York: Harcourt, Brace and World, 1966), pp. 115–120 Google Scholar. Strong, Donald S., “The Future of the Negro Voter in the South,” Journal of Negro Education, 26 (1957), 400–407 CrossRefGoogle Scholar. Daniel, Johnnie, “Negro Political Behavior and Community Political and Socioeconomic Structural Factors,” Social Forces, 47 (March, 1969), 274–280 CrossRefGoogle Scholar. A weaker relationship between these two variables is reported by Fenton, John H. and Vines, Kenneth N. in “Negro Registration in Louisiana,” American Political Science Review, 51 (1957), 704–713 CrossRefGoogle Scholar.

² The most notable example is the growth and operation of urban political machines during the 19th and early 20th centuries.

³ Matthews and Prothro, 115–117.

⁴ Thames, John P., “Population Migration Effects on Mississippi Poverty,” Mississippi Law Journal, 39 (May, 1968), 423–450 Google Scholar.

⁵ The county level voting returns for the 1968 presidential election are taken from Abney, F. Glenn, compiler, Mississippi Election Statistics (University, Miss.: Bureau of Governmental Research, 1968)Google Scholar, supplement, no pages given.

⁶ The general election was held in November, 1971. Charles Evers, running as an Independent, as did many other black candidates for local office, received 23 per cent of the total vote. County level returns are taken from … In the Public Interest (Millsaps College: Institute of Politics in Mississippi) Vol. 2 (June, 1972), 3 Google Scholar.

⁷ The reader is cautioned to remember that the relationships are for ecological variables and that the danger of unjustifiably inferring individual-level associations from correlation coefficients is great. Because individual cases have not been grouped (into counties) according to their scores on the dependent variables (black voter turnout in 1968 and 1971) unstandardized regression coefficients should be more revealing about individual level “effects.” Where opportune, regression slopes based on b scores will be used. For a lucid discussion on this point see Shively, W. Phillips. “‘Ecological’ Inference: The Use of Aggregate Data to Study Individuals,” American Political Science Review, 63 (December, 1969), 1183–1196 Google Scholar. See also Blalock, Hubert M. Jr., Causal Inferences in Nonexperimental Research (Chapel Hill: Univ. of North Carolina Press, 1964), chapter 4Google Scholar.

⁸ For a brief review of the literature and discussion of the employment of ecological data to measure contextual or structural variables see Valkonen, Tapani, “Individual and Structural Effects in Ecological Research” in Quantitative Analysis in the Social Sciences, ed. Dogan, Mattei and Rokkan, Stein (Cambridge, Mass.: The M.I.T. Press, 1969), pp. 53–68 Google Scholar.

⁹ Hubert M. Blalock, Jr. describes this as the “quantitative” criterion for evaluating the relative importance of independent variables in “Evaluating the Relative Importance of Variables,” The American Sociological Review, 26 (December, 1961), 866–874 CrossRefGoogle Scholar.

¹⁰ Salamon and Van Evera use percentage of black families who own their homes as a check on the occupational dependence variables but subsequently drop this index from their analysis. Including percentage of black homeownership with the other two vulnerability indices slightly increases the total multiple correlation coefficient. Upon close inspection the per cent of black homeownership was found largely to duplicate the effects of the occupational measures, and therefore it will not be employed in this analysis. Housing data were taken from the 1970 Census of Housing (part 26: Mississippi [Washington: G.P.O., 1971]Google ScholarPubMed).

¹¹ Median family income is closely related to community poverty levels, correlating −.93 with percentage of black families listed in poverty by the 1970 census, and .88 with the percentage having less than a 2,000 dollar yearly income.

¹² Recent cases of white election officials either misdirecting or not assisting black illiterate voters is documented in The Shameful Blight prepared by the Washington Research Project (Washington, October 1972), pp. 82–87 Google Scholar.

¹³ Forty-five rather than 50 per cent is used as the cut off for several reasons: (1) Because of differential outward migration some of these counties which in 1970 had less than a black voting age majority, may well have had a black majority in 1968. (2) In 1968 with the most recent census nine years old ambiguity probably existed as to the actual size of the potential black electorate and thus the same incentives to organize politically may have operated. (3) Since a 50 per cent cutoff produces only minor and inconsequential changes in the slopes given in Figure 1, and the 45 per cent provides a more desirable distribution of cases, the lower percentage figure is used here and in subsequent figures.

¹⁴ Matthews, and Prothro, , Negroes and New Southern Politics, Figure 5–1, p. 116 Google Scholar.

¹⁵ Ibid., p. 151.

¹⁶ There is some chance that this early negative slope may to some degree be an artifact of the composition of the counties' populations. In counties with very small black populations an even small white defection may greatly affect the percentage of black turnout, since the number of whites who defect may represent a relatively large percentage of the potential black electorate. Thus, the mean turnout percentage for the counties at the extreme left end of Figure 1 may be less accurate than for counties with larger black populations.

¹⁷ Watters, Pat and Cleghorn, Reese, Climbing Jacob's Ladder (New York: Harcourt, Brace and World, 1967)Google Scholar.

¹⁸ The counties which had received federal examiners by late 1967 are identified in Political Participation compiled by the United States Commission on Civil Rights (Washington: G.P.O., 1968), Table 9, pp. 244–247 Google ScholarPubMed.

¹⁹ There is good reason to believe that the presence of registrars is an important ingredient in black political mobilization. For example, by 1968, in Mississippi counties with federal examiners present, 71 per cent of the black eligible voters were registered as compared to only 50 per cent registered in nonexaminer counties. Rodgers, Harrell R. Jr. and Bullock, Charles S. III, Law and Social Change (New York: McGraw-Hill Book Co., 1972), p. 32 Google Scholar. Close observers of the civil rights movement in Mississippi have often asserted that the Child Development Group of Mississippi, the umbrella agency sponsoring Head Start projects in twenty-nine counties, created in its citizen advisory councils the core of political leadership in these counties. This variable was found to add little explanatory power to the effects of federal registrars, however.

²⁰ Watters and Cleghorn.

²¹ … In the Public Interest, p. 3.

²² … In the Public Interest, pp. 4, 6.

²³ Fred Wirt in his important study of integration in Panola County, Mississippi, reports that this consideration is appreciated by candidates of both races. “A candidate active among the other race stood to gain very few votes but more likely would mobilize even more voters against him because of the adverse racial reaction.” (Politics of Southern Equality [Chicago: Aldine, 1970], p. 161)Google ScholarPubMed.

²⁴ Salamon and Van Evera note that schoolteachers are highly vulnerable, but because the 1960 census included teachers in the category of “professionals” they could not be included among the highly vulnerable occupations. The 1970 census which lists teachers separately permits their inclusion among the highly vulnerable. The presence of this relatively small group, however, had almost no effect on the relationships.

²⁵ … In the Public Interest (Millsaps College: Institute of Politics in Mississippi), Vol. 1 (August, 1971), 1–14 Google Scholar.