... It is particularly bitter for Walker’s opponents that his rise has taken place in Wisconsin, a blue state with a long history of labor activism; it was the first state in the nation to grant collective-­bargaining rights to public employees, in 1959. Walker, who declined to be interviewed for this article, has won three races for governor, one a recall effort, and each time he took more than a third of the votes from union households. He was able to do this by making “labor” seem like someone else — even to union members — and pitting one faction against another. Four years ago, in a private exchange captured by a documentary filmmaker, he revealed his successful strategy to a billionaire supporter who asked him if Wisconsin would ever become a right-to-work state. Walker responded enthusiastically, explaining that Act 10 was just the beginning of a larger effort. “The first step is, we’re going to deal with collective bargaining for all public-­employee unions,” he said, “because you use divide-­and-­conquer.”...

At the foot of a hill in Bay View, a quiet Milwaukee neighborhood near Lake Michigan, stand seven pear trees. In front of them is a small wooden plaque that recounts the events of May 5, 1886, when some 1,500 workers, most of them Polish immigrants, marched on the Rolling Mills iron plant. The Milwaukee Iron Company built the plant and the neighborhood where its employees lived, and it demanded in return that they work as many as 16 hours a day, six days a week. A citywide strike for an eight-hour day and better working conditions had shut down every large factory in Milwaukee except Rolling Mills, and as the marchers began climbing the hill toward this last holdout, members of the Wisconsin National Guard fired down on them. They killed seven people, including a 13-year-old boy. Jeremiah Rusk, the governor of Wisconsin, had given the order. “I seen my duty, and I done it,” he later said. At the time he thought he might become president, but in the end he never ran. Until 1986, when the Wisconsin Labor History Society began holding an annual commemoration, the Bay View Massacre was largely forgotten. In 1996, the society planted the pear trees, one for each person killed.

Many of the great labor battles that followed the Bay View Massacre — Pittsburgh’s Homestead Strike of 1892; Colorado’s Ludlow Massacre of 1914 — also ended in violent defeat for the workers. Yet the defeats, in their very brutality, also forged a sense of solidarity that eventually produced great labor victories, including the eight-hour workday, enshrined into federal law during the Depression, and the passage of the 1935 Wagner Act, which guaranteed the right to strike and remains labor’s greatest means of leverage. That same year, the American Federation of Labor fully chartered A. Philip Randolph’s Brotherhood of Sleeping Car Porters, a black union. From 1935 to 1947, union membership in the United States quadrupled, from 3.5 million workers to nearly 15 million workers, fueled by the pro-­union policies of the New Deal and a labor shortage during World War II. By the mid-’50s, more than a third of American workers belonged to a union.

In 1941, when the movement was still ascending, William Ruggles, a 40-year-old editorial writer for The Dallas Morning News, coined the slogan “right to work.” Ruggles was alarmed by the growing strength of the labor movement, which in his view was intent on forcing all workers into unions. He proposed a constitutional amendment that would prohibit workers from having to pay dues to a union in order to hold a job in a “union shop.” “If the country does not want it, let us say so,” he wrote. “If we do want it, adopt it and maintain forever the right to work of every American.”

The day after the editorial was printed, a Houston political activist named Vance Muse called Ruggles to ask permission for his organization, the Christian American Association, to pursue the proposal. Ruggles agreed and suggested to Muse that he call it a “Right to Work Amendment.” Muse, an avowed racist — he told a United States Senate committee in 1936, “I am a Southerner and for white supremacy” — held a special animus toward unions, which he believed fostered race-­mixing. In “Southern Exposure,” a 1946 book about racism in the South, the muckraking journalist Stetson Kennedy quoted Muse’s pitch on the need for right-to-work, in which he said: “White women and white men will be forced into organizations with black African apes, whom they will have to call ‘brother’ or lose their jobs.”