12 SHELBY COUNTY v. HOLDER Opinion of the Court bach, 383 U. S., at 308, 315, 337. We recognized that it “may have been an uncommon exercise of congressional power,” but concluded that “legislative measures not otherwise appropriate” could be justified by “exceptional conditions.” Id., at 334. We have since noted that the Act “authorizes federal intrusion into sensitive areas of state and local policymaking,” Lopez, 525 U. S., at 282, and represents an “extraordinary departure from the traditional course of relations between the States and the Federal Government,” Presley v. Etowah County Comm’n, 502 U. S. 491, 500–501 (1992). As we reiterated in Northwest Austin, the Act constitutes “extraordinary legislation otherwise unfamiliar to our federal system.” 557 U. S., at 211. B In 1966, we found these departures from the basic features of our system of government justified. The “blight of racial discrimination in voting” had “infected the electoral process in parts of our country for nearly a century.” Katzenbach, 383 U. S., at 308. Several States had enacted a variety of requirements and tests “specifically designed to prevent” African-Americans from voting. Id., at 310. Case-by-case litigation had proved inadequate to prevent such racial discrimination in voting, in part because States “merely switched to discriminatory devices not covered by the federal decrees,” “enacted difficult new tests,” or simply “defied and evaded court orders.” Id., at 314. Shortly before enactment of the Voting Rights Act, only 19.4 percent of African-Americans of voting age were registered to vote in Alabama, only 31.8 percent in Louisiana, and only 6.4 percent in Mississippi. Id., at 313. Those figures were roughly 50 percentage points or more below the figures for whites. Ibid. In short, we concluded that “[u]nder the compulsion of these unique circumstances, Congress responded in a