In a condescending but shallow response to a Huffington Post piece written last week by my colleague Emily Phelps and me, Wall Street Journal columnist James Taranto accuses us of appealing to “emotion” and wallowing in “nostalgia for the heroism of the civil rights movement half a century ago.” Our piece mourned the recent death of Lawrence Guyot, a civil rights hero who was repeatedly “challenged, jailed and beaten” in his efforts to register black voters in Mississippi in the 1960s, while making broader points about the continued need for the law — the Voting Rights Act of 1965 — that represents one of the most important accomplishments produced by the struggles of Mr. Guyot and his civil rights movement compatriots.

Forgive us for getting a bit worked up in explaining that Mr. Guyot’s untimely death coincides with a time when conservatives are seeking simultaneously to enact laws that suppress the vote and to have their conservative majority on the Supreme Court strike down a key part of the Voting Rights Act, but the strongest argument in favor of the Act is not based on emotion, it’s based on the Constitution. Mr. Taranto accuses us of not having “a lot to say about the Constitution,” but this is willful blindness on Taranto’s part. Unlike Mr. Taranto, who writes opinion columns for a living, my organization, Constitutional Accountability Center, produces scholarship and writes legal briefs. For the last three years, dating back even before the Shelby County case was filed in 2010, CAC has filed briefs, written reports and authored numerous blog posts that set out why the text and history of the Fifteenth Amendment support the constitutionality of the Voting Rights Act.

As history shows, the Framers of the Fifteenth Amendment recognized that the hard-won gains towards what Lincoln called “government of the people, by the people, and for the people” would be frustrated unless Congress had the power to protect the right to vote against all forms of racial discrimination in voting, whether heavy-handed or subtle. The Framers knew that states hostile to the Fifteenth Amendment could use their power to regulate elections to frustrate the Fifteenth Amendment’s guarantee, and made sure to give Congress the power to secure to racial minorities full enjoyment of the right to vote. Taranto is loath to admit it, but, on any faithful reading of our Constitution, Congress has the power of selecting the means of protecting one of our most cherished constitutional rights from racial discrimination.

Mr. Taranto’s willful blindness goes even further. He ignores completely the massive record assembled by Congress in 2006, when bipartisan majorities (by votes of 98-0 in the Senate and 390-33 in the House) renewed the preclearance requirement of the Voting Rights Act for a fifth time. Congress found repetitive violations of minority voting rights, including a number of intentionally discriminatory practices — redistricting decisions made on the basis of race, intimidation and harassment at the polls, closing or relocating polling places and even cancelling elections to deprive African Americans of the right to vote — that persisted in jurisdictions covered by the Act. As conservative jurist Judge John Bates wrote in his district court opinion in Shelby County rejecting a constitutional challenge to the preclearance provision, there is “extensive evidence of recent voting discrimination reflected in th[e] virtually unprecedented legislative record.”

The evidence from the most recent presidential election — where preclearance played a vital role in protecting the right of racial minorities to vote — only adds to the overwhelming record. While voter suppression efforts occurred across the country, they were concentrated in the states where preclearance applies, as this fact sheet makes clear. In short, the actual record demolishes Mr. Taranto’s claim that supporters of the Voting Rights Act are simply “clinging to the policies of the past.” Instead, the record demonstrates that it is Mr. Taranto who is blinding himself to realities of today and the mountain of facts found by Congress in exercising the constitutional authority explicitly conferred on it by the Fifteenth Amendment.

For the last 47 years, year in and year out, the Voting Rights Act has stood as our nation’s most effective weapon to realize the guarantees of the Fifteenth Amendment and prevent and deter state-sponsored racial discrimination in voting. If the Supreme Court is faithful to the text and history of the Fifteenth Amendment, it should resoundingly affirm the constitutionality of the Voting Rights Act.