What is the test for determining whether a challenged voting practice violates Section 2 of the Civil Rights Act?

In determining whether a challenged voting practice violates 2, the district court must examine the totality of the circumstances and "determine, based 'upon a searching practical evaluation of the past and present reality,'... whether the political process is equally open to minority voters." Thornburg v. Gingles, 478 U.S. 30, 79, 106 S.Ct. 2752, 2781, 92 L.Ed.2d 25 (1986) (citation omitted). This examination is intensely fact-based and localized. Id. (citing Rogers v. Lodge, 458 U.S. 613, 621, 102 S.Ct. 3272, 3277-78, 73 L.Ed.2d 1012 (1982)). Deferring to the district court's superior fact-finding capabilities, we review only for clear error its ultimate finding of no 2 violation. Id. at 78-79, 106 S.Ct. at 2780-81.