In 1954, when James (Big Jim) Folsom was running for a second term as governor of Alabama, he drove to Clayton, in Barbour County, to meet a powerful judge.* This was in the heart of the Deep circuit-court South, at a time when Jim Crow was in full effect. In Barbour County, the races did not mix, and white men were expected to uphold the privileges of their gender and color. But when his car pulled up to the curb, where the judge was waiting, Folsom spotted two black men on the sidewalk. He jumped out, shook their hands heartily, and only then turned to the stunned judge. “All men are just alike,” Folsom liked to say.

Big Jim Folsom was six feet eight inches tall, and had the looks of a movie star. He was a prodigious drinker, and a brilliant campaigner, who travelled around the state with a hillbilly string band called the Strawberry Pickers. The press referred to him (not always affectionately) as Kissin’ Jim, for his habit of grabbing the prettiest woman at hand. Folsom was far and away the dominant figure in postwar Alabama politics—and he was a prime example of that now rare species of progressive Southern populist.

Folsom would end his speeches by brandishing a corn-shuck mop and promising a spring cleaning of the state capitol. He was against the Big Mules, as the entrenched corporate interests were known. He worked to extend the vote to disenfranchised blacks. He wanted to equalize salaries between white and black schoolteachers. He routinely commuted the death sentences of blacks convicted in what he believed were less than fair trials. He made no attempt to segregate the crowd at his inaugural address. “Ya’ll come,” he would say to one and all, making a proud and lonely stand for racial justice.

Big Jim Folsom left office in 1959. The next year, a young Southern woman published a novel set in mid-century Alabama about one man’s proud and lonely stand for racial justice. The woman was Harper Lee and the novel was “To Kill a Mockingbird,” and one way to make sense of Lee’s classic—and of a controversy that is swirling around the book on the eve of its fiftieth anniversary—is to start with Big Jim Folsom.

The Alabama of Folsom—and Lee—was marked by a profound localism. Political scientists call it the “friends and neighbors” effect. “Alabama voters rarely identified with candidates on the basis of issues,” George Sims writes in his biography of Folsom, “The Little Man’s Best Friend.” “Instead, they tended to give greatest support to the candidate whose home was nearest their own.” Alabama was made up of “island communities,” each dominated by a small clique of power brokers, known as a “courthouse ring.” There were no Republicans to speak of in the Alabama of that era, only Democrats. Politics was not ideological. It was personal. What it meant to be a racial moderate, in that context, was to push for an informal accommodation between black and white. ...