In the spring of 2012 Lisa Nelson, then in the government relations department for Visa, received what she calls the "corporate blackmail letter." The letter had gone to Visa's CEO and all the board members.

As Kim Strassel recounts in a Wall Street Journal column this morning based on her new book, The Intimidation Game: How the Left Is Silencing Free Speech, out tomorrow, the threatening letter came from Color of Change, a black advocacy organization founded by Rashad Robinson, an activist, and by former Obama adviser Van Jones.

Similar letters had been received by board members at McDonald’s, John Deere, Coca-Cola, Pepsi, Amazon, Wendy’s, Procter & Gamble. The companies were told that if they did not cease contributing to American Legislative Exchange Council (ALEC), an organization that promotes a pro-business atmosphere in state legislatures, they would be subject to a smear campaign.

ALEC ostensibly was being blamed for a "stand your ground" law in Florida, which allows someone to protect themselves in the face of a perceived threat and which became a hot button issue in the wake of the death of Trayvon Martin, a 17-year-old African American who was killed by neighborhood watch member George Zimmerman.

The companies in turn would be blamed for Trayvon Martin's death, the letter warned their leadership, if they did not withdraw support from ALEC. Strassel explains what was behind the threatening letters:

The Trayvon Martin shooting was a new way for progressives to go after ALEC. They had long despised the group, but attacking ALEC took on a new urgency after the 2010 midterm elections, when voters had revolted against unpopular liberal policies and programs. Democrats sustained staggering losses on the federal and state levels. Republicans had unprecedented control over state legislatures and governors’ mansions, and a new ability to green-light reforms that ALEC proposed.

In an interview with Bloomberg in May 2012, Common Cause spokeswoman Mary Boyle explained that her group had been waiting for months for the right moment to file a complaint with the IRS to strip ALEC of its nonprofit status. “The Trayvon Martin thing was like a gift,” she said, in an extraordinary, if horrifying, moment of honesty.

Within weeks of the shooting in February 2012, a liberal coalition had mobilized against ALEC, elevating an organization few Americans had ever heard of to the status of national pariah, responsible for laws that the left now refers to as “kill at will” statutes. A rogues’ gallery of left-wing groups, including MoveOn.org, People for the American Way and Color of Change, demanded that ALEC make its funding sources public.

Although ALEC, where Nelson subsequently became CEO, was not required to reveal its donors, many companies over the years had made known their support. Eighty-five thousand Color of Change members received letters urging them to boycott companies that gave money to the pro-business organization. The campaign was effective:

Coca-Cola crumpled quickly, in early April publicly declaring that it would pull its donations to ALEC. Then the lemmings started jumping blindly. By the end of the carnage, ALEC had lost as many as 100 major companies, a significant portion of its mixed (small and large) 500-company membership. It was a huge hit. ALEC, a lean organization routinely operating with a budget of about $7 million, was at risk of losing it all.  

Democratic Senator Dick Durbin wrote three hundred letters invoking the Trayvon Marton shooting to organizations he believed to be ALEC funders. Stassel calls the Durbin letter half intimidation and half a fishing expedition–it was designed partly to ferret out more donors to intimidate.

The Durbin letter backfired:

The Durbin roster seemed to reflect little more than having put any name that had ever been mentioned in the same sentence as ALEC on a list, and adding a few more for good measure. Some of the targets were downright amusing. The owner of a car dealership in Louisiana got a Durbin letter simply because ALEC had once done an event on his lot.

Up to now, ALEC had been on its heels. But Mr. Durbin miscalculated. He seemed unaware that the group had revamped its PR shop and moved into fight mode. Mr. Durbin had also struck during ALEC’s annual meeting, perhaps figuring the letter would cause internal disarray. It had the opposite effect. “Everyone that mattered was all in the same room; we were able to articulate a plan of action,” says Mr. Meierling. “It galvanized us, because no one could believe he’d do such a thing.”

Mr. Meierling points out that the Durbin letter became a big turning point for many on the right. “It got people to realize there is a huge difference between secrecy and privacy,” he says. “And that everyone has the right to associate freely, the right to debate free ideas.” By the time the Durbin hearing happened, a senator chastened by widespread condemnation took the stage. Mr. Durbin barely mentioned ALEC, turning the hearing instead into a look at gun violence. He’d been called out.

The starting point for the Strassel's book was the Supreme Court's Citizens United decision, which protects free speech and has so angered the left.