Racially Polarized Voting in the South: Quantitative Evidence from the Courtroom

Abstract

Within the last 15 years historians, political scientists, and sociologists have played major roles as expert witnesses in southern voting-rights cases. In most of these lawsuits, black plaintiffs challenged the racially discriminatory effects of at-large elections, contests in which candidates must run citywide or countywide rather than from single-member districts. Unless a white majority casts its votes as a bloc against minority candidates, at-large elections do not have a discriminatory impact. For this reason, the court’s decision frequently turns on its assessment of the degree to which electoral patterns in the jurisdiction are polarized along racial lines. Although the expert witnesses on whom the court must rely have employed a variety of statistical methods, they increasingly have preferred a technique known as ecological regression analysis to measure the degree of racial bloc voting (Loewen 1982: 179–94; Grofman et al. 1985; Engstrom and McDonald 1985; Jacobs and O’Rourke 1986).