In Dunning’s polite brand of white supremacy, black voting during Reconstruction — which for a while brought political revolution and hundreds of black elected officials to the South — was a curse and a historical blunder. The “political equality of the negroes,” he maintained, went too far and necessitated a counterrevolution to roll it back.

Dunning never used our modern term, suppression. He called it “pressure applied by all these various methods” to reduce the black vote. Indeed, the “undoing” of Reconstruction could be measured, as Dunning celebrated, in the large reductions of black voter turnout in Southern states. Votes were not suppressed; they simply “disappeared,” he said, like bad weather.

In the 1884 presidential election compared with that of 1876, the black vote declined from 182,000 to 91,000 in South Carolina, 164,000 to 120,000 in Mississippi and 160,000 to 108,000 in Louisiana. As the Jim Crow system descended on Southern life, black voters became increasingly “extinct,” Dunning wrote. Dr. Anderson documents this “voter mortality rate” by the early 20th century: Between 1896 and 1904, registered black voters in Louisiana plummeted from 130,000 to 1,342, and in Alabama from 180,000 to 3,000. Today’s Republicans can only dream of such numbers, but they need only fractions of those counts to succeed. Their trickery matches their challenge. We should not mince words: Voter mortality is their goal.

Fueling Dunning’s confidence about Jim Crow’s control over voting was the coup and bloody massacre committed by white Democrats in Wilmington, N.C., in the election of 1898. The largest city in the state, Wilmington had forged a black majority and a successful black economic and political leadership. White Democrats found black rule and economic success unbearable. In a vicious white-supremacist campaign led by a Confederate veteran and congressman, Alfred Waddell, whites used lies, intimidation, cartoon journalism and racial terrorism to take back control first of the city and then of the entire state. Organized mobs, energized by grievance and racial hatred, violently overthrew the election.

In rousing speeches, Waddell made their “duty” clear to the mobs of Wilmington. “This city, county and state shall be rid of Negro domination, once and forever,” he shouted at an election-eve rally. “Go to the polls tomorrow and if you find a Negro voting, tell him to leave the polls. And if he refuses, kill him! Shoot him down in his tracks!” The mob roared and raised their rifles in the air. On and after Election Day, 15 to 20 people were murdered in the immediate uprising, while hundreds of black women and children fled into nearby swamps. About 1,400 fled the city during the next 30 days.

Generations later, the right to vote never seemed so important and newly triumphant as on the day President Lyndon Johnson signed the Voting Rights Act in 1965. The violence on the Edmund Pettus Bridge in Selma, Ala., in the early spring, and the heroic march that it inspired; a brave and persistent civil rights movement; liberal Democrats joined by a key cadre of moderate Northern Republicans in Congress; and a converted, dedicated former segregationist in Johnson, who embraced his most important historic moment — all of this made the act possible. But it became law against the same resistance and rhetoric left over from the past.

W.B. Hicks, the leader of the white-supremacist Liberty Lobby, told Congress: “If the president’s law is passed, the South will disappear from the civilized world just as surely and certainly as Haiti did in 1804.” Senator Sam Ervin of North Carolina trotted out numerous notorious segregationists to testify before his Senate Judiciary Committee. Leander Perez, the Democratic leader of a Louisiana parish, invoked the Dunning school vision of Reconstruction. The bill “was worse than the Thaddeus Stevens legislation during Reconstruction,” he said. “It is inconceivable that Americans would do that to Americans.” The new power of the Voting Rights Act empowered the Justice Department to scrutinize any changes to voting laws and practices (so-called preclearance) in seven states and other regions of the country with especially notorious records of denying the franchise.