It is hard to imagine an area in which Congress has more express constitutional authority to act than in protecting the right of minorities to vote.

When the Civil War ended and the hard work began in creating a nation with a single standard of citizenship, the 14th Amendment was adopted to make it clear that blacks had equal rights. The 15th Amendment said the right to vote could not be denied or abridged on account of race.

Both amendments gave Congress the “power to enforce” them “by appropriate legislation.”

But that is not how much of the current Supreme Court — perhaps a majority — seem to see it. The case — widely considered this term’s most watched — is a challenge to the heart of the Voting Rights Act, its Section 5. The court may be on the brink of ruling that Congress did not have the power to reauthorize it.

The post-Civil War amendments were a turning point. The first 11 amendments were a list of things the government could not do, and the 12th Amendment was a technical fix.

The 13th Amendment, which barred slavery, the 14th Amendment and the 15th Amendment were the first to give the federal government new powers. The nation had a large problem, eradicating the vestiges of slavery and racial inequality, and it knew that Congress needed potent tools to get the job done.

When the framers drafted these amendments, they were worried that Congress would have too little power to get the job done, not too much. Senator Lyman Trumbull warned that if Congress’s authority were interpreted too narrowly, “the trumpet of freedom that we have been blowing throughout the land has given an ‘uncertain sound,’ and the promised freedom is a delusion.”

It was not until the civil rights movement of the 1950s and ’60s that Congress got serious about the assignment laid out in the post-Civil War amendments. It passed the Voting Rights Act in 1965 when about 7 percent of blacks in Mississippi were registered to vote. The act outlawed literacy tests, directed the attorney general to challenge poll taxes and, in Section 5, required certain covered jurisdictions to “pre-clear” any new election rules with the Justice Department or a federal court to ensure that they did not disenfranchise minorities.

The following year, the Supreme Court upheld the Voting Rights Act, and it did so in three more cases. Congress has also been steadfast in its support for the act over the years, as have the presidents who have repeatedly signed laws renewing and extending it. Before renewing the act in 2006, Congress held 21 hearings and collected 16,000 pages of testimony to determine that it was still needed. The Senate then voted in favor of renewal by 98-to-0, the House by 390-to-33 and former President George W. Bush signed it.

So what is the problem? The Voting Rights Act has run smack into the “federalism” crusade of the court’s conservative bloc. For more than a decade, it has been ruling in an array of areas that Congress’s power to pass laws is far more limited than it has long been thought to be. Judge John T. Noonan Jr., who was appointed to a federal appeals court by former President Ronald Reagan, has lamented that as a result, the Supreme Court has begun “monitoring Congress the way appellate courts monitor administrative agencies.”

At the oral argument in the Voting Rights Act case last month, the conservative justices were full of their own ideas about what would be good voting rights policy. Chief Justice John Roberts seemed unhappy that the act applies to more states in the South than the North. Justice Antonin Scalia seemed to think that Virginia should not be covered by the act since it was “the first state in the union to elect a black governor.”

Justice Scalia even asked, “Do you ever seriously expect Congress to vote against a re-extension of the Voting Rights Act?” Apparently, the fact that there is such overwhelming support for the act is an argument for why the Supreme Court should strike it down.

There is a lot of talk in conservative circles about judicial modesty and deferring to the political branches. That view of judging often overlooks the important role that courts have in protecting people’s rights. But if there was ever a time to defer, it is when Congress is protecting voting rights in the exact way the Constitution directs it to.