Gregory B. Craig, a Washington lawyer, was White House counsel from January 2009 to January 2010.

On Aug. 6, 1965, I was working in Coahoma County, Miss., trying to register new voters at the courthouse in Clarksdale. For many weeks, I and other civil rights workers in our project had been knocking on doors, persuading African Americans to go down to the courthouse, stand in line, risk retaliation, take a detailed written test and, inevitably, be rejected as unqualified. We would then ask each rejected applicant to sign an affidavit. We collected those affidavits and sent them in bundles to the Civil Rights Division of the Justice Department. The purpose of this effort was to show that African Americans in the South wanted to vote and that this particular person had been prevented from registering for no reason other than his or her race. That summer, we persuaded 500 African American citizens in Coahoma County to try to register to vote. Four or five passed the test. The rest signed affidavits. We prayed that federal officials would read the affidavits and do something about the situation.

The summer of 1965 was hot and tense, but it was not as violent as the previous summer, when three workers were murdered in Neshoba County and when the chief of police in Clarksdale, Ben Collins, reportedly shot a black boy in the head in a public playground. Nonetheless, I lived in fear. I was afraid that I would get a flat tire after dark and that the police would pull me over, charge me with breaking the speed limit and take me to lock-up or that, out on the dusty streets of these small Delta towns, I might meet a crowd of angry white guys with nothing better to do than to beat the crap out of a civil rights worker.

Recently, we had been knocking on doors in Friars Point, a tiny town in the middle of a cotton field next to the levee. We were organizing a mass meeting at the Friars Point church where, we hoped, folks would come to find out how and where to register. We also hoped that the singing, the music, the speeches and the spirit would give us new energy for another week of work.

Just before we left Clarksdale to drive out to Friars Point the night of Aug. 6, we learned that President Lyndon Johnson had signed the Voting Rights Act of 1965 and that the U.S. government would be sending federal registrars to Mississippi. At the church, we made the announcement to the people who had come to our meeting. Real change was on the way, we told them. I recall using the phrase, “There is a new world coming.” People sang and spoke. An older man got up and said that he was a school bus driver, that he had been wounded while serving in the Army during the war and that he still carried shrapnel in his body. He had never been allowed to vote, he said, and had not had the courage even to try. He said he would have his bus in front of the church the following Tuesday morning to carry anyone who needed a ride down to the courthouse.

That was a moment of real hope and change.

Many months later, I asked one of my Harvard professors — a distinguished legal historian who was also the biographer of Oliver Wendell Holmes — whether there was any concern about the constitutionality of Congress passing a law that imposed requirements on some states when it did not impose the same requirements on other states. He said: “No. We fought a very bloody war about that same question: the proper role of the federal government when it came to protecting the rights of an American citizen. The South lost that war; and in 1870 the country, to make itself absolutely clear on that issue, adopted the 15th Amendment. That amendment put the issue to rest.”

I looked up the amendment, which has two parts. The first part says: “(1) The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color, or previous condition of servitude.” The second part says: “(2) The Congress shall have power to enforce this article by appropriate legislation.” This amendment specifically empowers the most political branch of our national government to act to protect every American’s right to vote whenever and wherever Congress deems that right to be in jeopardy. It is hard to conceive of a legal or constitutional basis to justify the Supreme Court acting now to disable such a clear-cut grant of power.

The 15th Amendment has been on the books for 143 years. The Voting Rights Act of 1965 has been with us for almost 50 years. Over those years, the Supreme Court has reviewed the act and declared it constitutional on more than one occasion. In 2006, Congress held hearings, took evidence and reauthorized the act — almost unanimously. If any American has complaints or criticisms about the way the law is drafted or implemented, that person — like all American citizens — has the right to petition Congress and ask that the law be changed. But the law is not unconstitutional.

For this Supreme Court to find the Voting Rights Act of 1965 unconstitutional would be to forget the Civil War and ignore the 15th Amendment. It would be the greatest example of judicial activism in generations. Such an opinion would bring the Supreme Court to its lowest point in 150 years.

Most experts think it is going to happen.