five percent in 1940 to twenty-eight percent in 1960. Although the Fifteenth Amendment was never interpreted to prohibit poll taxes, in 1962 the Twenty-fourth Amendment was adopted banning poll taxes in federal elections, and in 1966 the Supreme Court ruled in Harper v. Virginia State Board of Elections (1966) that state poll taxes violate the Fourteenth Amendment's Equal Protection Clause. Congress used its authority pursuant to Section2 of the Fifteenth Amendment to pass the Voting Rights Act of 1965, achieving further racial equality in voting. Sections 4 and5 of the Voting Rights Act required states and local governments with histories of racial discrimination in voting to submit all changes to their voting laws or practices to the federal government for approval before they could take effect, a process called "preclearance". By 1976, sixty-three percent of Southern blacks were registered to vote, a figure only five percent less than that for Southern whites. The Supreme Court upheld the constitutionality of Sections 4 and5 in South Carolina v. Katzenbach (1966). However, in Shelby County v. Holder (2013), the Supreme Court ruled that Section 4(b) of the Voting Rights Act, which established the coverage formula that determined which jurisdictions were subject to preclearance, was no longer constitutional and exceeded Congress's enforcement authority under Section2 of the Fifteenth Amendment. The Court declared that the Fifteenth Amendment "commands that the right to vote shall not be denied or abridged on account of race or color, and it gives Congress the power to enforce that command. The Amendment is not designed to punish for the past; its purpose is to ensure a better future." According to the Court, "Regardless of how to look at the record no one can fairly say that it shows anything approaching the 'pervasive', 'flagrant', 'widespread', and 'rampant' discrimination that faced Congress in 1965, and that clearly distinguished the covered jurisdictions from the rest of the nation." In dissent, Justice Ruth Bader Ginsburg wrote, "Throwing out preclearance when it has worked and is continuing to work to stop discriminatory changes is like throwing away your umbrella in a rainstorm because you are not getting wet." While the preclearance provision itself was not struck down, it will continue to be inoperable unless Congress passes a new coverage formula. See also Ballot access Black suffrage Forty acres and a mule Nineteenth Amendment to the United States Constitution (1920, women's right to vote) Twenty-sixth Amendment