For labor legends such as Genora Johnson Dollinger, who led a confrontational 1937 strike that forced concessions from the all-powerful General Motors, it has been an agonizing few decades. “Anybody who … went through all those upheavals must feel disillusioned, discouraged and disgusted with present-day labor leadership,” she said to journalist Studs Terkel 15 years ago. “Labor is in for some pretty dark days.”

Theories abound on whom labor should blame for its decay. The American Prospect editor Robert Kuttner sums up the liberal theory that the decline was caused by “a no-holds-barred attack by corporations on unions, with the complicity of government.”

In his new book “Restoring the Power of Unions: It Takes a Movement,” labor historian Julius Getman acknowledges these factors, but he calls them “simple and comforting explanation[s] for a complex process.”

“Unions bear significant responsibility for their own demise,” he writes.

That’s because they’ve neglected to use the corporate (or “comprehensive”) campaign, he argues, in which a union builds community support and attacks the company’s weak spots, labor-related or not, creating a protracted standoff for which the company must constantly open its wallet to address an unpredictable series of public relations snafus.

Many labor leaders see the traditional methods of resistance — strikes and National Labor Relations Board arbitration — as economically risky and mostly ineffectual. Strikes often result in worker replacement, and the NLRB specifically refuses to investigate or consider the empirical implications of its decisions. But the comprehensive campaign, while long and energy-intensive, creates a sense of empowerment and solidarity among the rank and file.

And when it works, it works. The average NLRB arbitration begins with a vote from local workers and ends with either no bargaining order or a bargaining order that does not require the employer to offer a fair contract. That’s why labor leader Bill Bradfield’s local union turned down holding an NLRB election that it was likely to win: “We got sick of winning elections and not having agreements,” he told Getman. “But when you have a comprehensive campaign, if you get recognition, you’re going to get an agreement.”

That’s also why Getman rejects mainstream labor’s sacred cow: the Employee Free Choice Act. Under current law, workers form a union chapter by gathering petition signatures in a “card check,” which can lead to a union-formation election if 30 percent of the work force signs. EFCA, currently being considered in Congress, would take away the election part, leaving the nonsecret card-check as the only form of vote.

While it would also strengthen punishments for employer retaliation, Getman argues that EFCA would not address employers’ near-exclusive access in influencing their workers and would simply quicken the union’s campaign — and, in response, the employer’s. “It is the campaign, not the election, that poses the problem for unions,” Getman writes.

Getman also says that the top-down method in which labor has lobbied for EFCA speaks for itself. “The membership played no role in this action,” he says. “Whereas, about ten years ago, when there was a real effort to change the law on strike replacement, the members were really stirred up, and pushed the leaders to take action. And I think they’re only strong when the members are involved. In everything. Political action, strikes — that’s what their strength is.”

Major aspects of Getman’s book have already been vindicated. Last week, Unite Here, the union he praises most for its dedication to bottom-up comprehensive campaigning, walked away victorious from an aggressive takeover attempt by the country’s most powerful union, the Service Employees International Union.

Initiated by recently retired SEIU President Andy Stern, the move included Vice President Bruce Raynor’s alleged embezzling of millions of dollars from Unite Here’s strike fund.

Being inextricably linked to the health of the economy, labor faces a tough road. High unemployment is bound to weaken unions’ already diminishing position at the bargaining table. Fewer than one in 10 private-sector workers are unionized today, down from a third in the early 1950s.

Perhaps the vociferous rejection of Stern’s size-over-solidarity philosophy signals a sea change, as his handpicked successor was rejected by SEIU. For better or for worse, there is movement.