More than seventy years ago Congress designed the nation’s basic labor law to encourage–not just permit but encourage–workers to organize and bargain collectively with their employers. More than any government since then, the Bush Administration has been committed to just the opposite–stifling the right of workers to organize.

Most dramatic, in an arcane ruling on what it means to be a supervisor, Bush’s NLRB in late September took away the legal protection for millions of workers to join a union. It may count as the most significant assault on workers’ rights since the passage of the Taft-Hartley Act in 1947, but it is perfectly consistent with other actions by this Administration. The NLRB had already restricted the right to organize of graduate student employees, temporary workers and the disabled, and Bush abolished collective bargaining for federal workers in Homeland Security and the Transportation Security Administration (and tried to do the same at the Defense Department). Add to this the fact that unionbusting employers enjoy virtual immunity, and it’s clear why the ranks of the labor movement are thinning even as 57 million Americans say they would join unions if given a free choice to do so.

In its recent “Kentucky River” cases, named for a Supreme Court case on the status of supervisors, the NLRB ruled that workers like “charge nurses” at a hospital who give low-level assignments to co-workers count as supervisors and thus are not guaranteed the right to join a union. In 1947 foremen were banned from joining unions, but “minor supervisory employees” were allowed to keep their union rights. The new definition by the Bush-appointed majority would exclude about 8 million workers who exercise such minor supervision in industries from healthcare to manufacturing to construction, according to the Economic Policy Institute. The dissenters on the NLRB argued that as a result of this latest decision, most professionals–soon nearly a quarter of the workforce–could be denied the right to unionize.

It is uncertain who will be affected. Employers can choose when they want to fight over which workers are supervisors, and the definitions are open to interpretation. That guarantees endless litigation and delays, making the NLRB election procedure even more of a barrier to collective bargaining than it already is. Frustrated with the labor board’s onerous procedures, unions already do four-fifths of their organizing by directly pressuring companies for recognition when a majority of workers sign union cards. One of labor’s top legislative priorities, the Employee Free Choice Act, which guarantees workers the right to use this “card check” procedure, has 216 House and forty-five Senate sponsors.

Beyond crushing workers’ rights, the supervisor decision is out of touch with today’s workplace, where professional and technical workers are still workers in need of a collective voice, even if they do have more discretion than factory assemblers, and where businesses try to classify relatively routine work as managerial to increase control over and loyalty from workers. AFL-CIO attorney Craig Becker speculates that Wal-Mart could create teams of its “associates” who would rotate responsibility for assigning who puts what stock on which shelves, potentially making them all managers under the NLRB’s new definition. Ploys like this would vastly expand the number of workers removed from unions.

Unions are still the main force for economic justice; indeed, 15 percent of the increase in wage inequality among men in the past twenty-five years is due to deunionization. The NLRB decision also has political implications. More union members means more votes for progressive, usually Democratic, candidates (see David Moberg, “Laboring Toward Election Day,” page 21). Labor plans to fight back: at the bargaining table, in organizing drives, in the courts and with new laws to narrow the exclusion of supervisors. It’s a fight, like all fights for workers’ rights, that’s crucial not just for unions but for the entire progressive movement.