Few of today’s politicians or political writers have even heard of Clair Engle. I had to learn his name, in grade school civics courses in California, because he was one of our state’s two U.S. senators. (No one will remember the other: Thomas Kuchel, pronounced keekle, a Republican who succeeded none other than Richard Nixon as senator when Nixon became vice president under Dwight Eisenhower.) Engle was a Democrat, who when elected in 1958 took a seat that Republicans had held since 1890s. While in office he was known mainly for supporting California-related public works programs, and for flying his own airplane all around to see constituents, including through the vast, rural Second District that made up most of the northern part of the state and that he had represented as a congressman.

Then in the summer of 1963, when Clair Engle was 51 years old, a generation younger than John McCain today, he was diagnosed with a brain tumor, and underwent surgery. Within six months, he was partially paralyzed and unable to speak. Within a year of his diagnosis, in the summer of 1964, he was dead, at age 52.

But in those final few months, Clair Engle chose to do something remarkable—in fact the main thing for which he is now known.

In the spring and summer of 1964, soon after John Kennedy’s assassination and also the Birmingham Church bombing that gave new urgency to Martin Luther King Jr.’s leadership of the civil-rights movement, the Congress was considering what became the Civil Rights Act of 1964.

Southern senators led by then-Democrat Strom Thurmond were filibustering the bill. In those days, filibusters were real, with senators orating for hours on the floor, and it took a two-thirds vote, or 67 senators, to break them. By the time of the crucial cloture vote on June 10, 1964, Clair Engle was too sick to stand or speak, and he was in his final weeks of life. But he was brought to the Senate floor, and when the clerk read his name, “Mr. Engle—Yay or Nay,” to see whether he would vote in favor of cloture, Clair Engle lifted his hand toward his eye, signaling an “Aye” vote. He voted to end the filibuster and enact the historic civil-rights bill.

As it happened, and as with John McCain’s “decent family man” comment, this was one inch away from dramatic perfection. It turned out that Clair Engle did not “need” to come to the floor to cast that vote (although Engle may not have known that beforehand). Seventy-one senators supported an end to Strom Thurmond’s filibuster, so the bipartisan non-Southern bloc supporting the bill could have done without him. But Clair Engle, although he could not stand, wanted to take a stand, and did. And if he is remembered, this will be the reason why.