White v. Regester , 412 U.S. 755 (1973), strongly shaped litigation through the 1970s against at-large systems and gerrymandered redistricting plans. In Mobile v. Bolden , 446 U.S. 55 (1980), however, the Supreme Court required that any constitutional claim of minority vote dilution must include proof of a racially discriminatory purpose, a requirement that was widely seen as making such claims far more difficult to prove.

The 1982 Amendments

Congress renewed in 1982 the special provisions of the Act, triggered by coverage under Section 4 for twenty-five years. Congress also adopted a new standard, which went into effect in 1985, providing how jurisdictions could terminate (or "bail out" from) coverage under the provisions of Section 4. Furthermore, after extensive hearings, Congress amended Section 2 to provide that a plaintiff could establish a violation of the Section without having to prove discriminatory purpose.