The first recorded court case involving worker organizing in the United States dates back to Thomas Jefferson’s second term. Shoemakers picketing for higher wages were convicted of using “threats, menaces and other unlawful means” to maintain a conspiracy.

That set the tone for jurisprudence of workers’ rights in the new republic, where conservative jurists treated union organizing as a criminal activity. As a result, unions spent the 19th and early 20th centuries decrying “judge-made law” and demanding the codification of their rights.

These demands resulted in a landmark victory. The 1935 NLRA encouraged collective bargaining by establishing a federal agency, the National Labor Relations Board (NLRB), to certify the existence of a union at a workplace and sanction employers who refused to deal with a bona fide union.

Another point of the NLRA was to keep labor disputes out of the courts. Most unions have stuck with the intent of the Act and shied away from pursuing rights and benefits that cannot be won at the bargaining table. Employers have shown no such reticence. They’ve attacked workers’ rights in the courts since the day the NLRA was passed, steadily chipping away at hard-won protections.

A fundamental flaw in the Act opened the door to these successful attacks. The NLRA’s authority derives from the Constitution’s commerce clause. Legal experts at the time argued that this framing had the best shot at withstanding legal challenges under a Supreme Court hostile to New Deal legislation.

Representatives of the American Federation of Labor (AFL) had, instead, pushed hard to base the Act on the 13th Amendment, which banned slavery and involuntary servitude. The AFL’s Andrew Furuseth warned of settling for short-term legislative gains while leaving unsettled the legal question of “whether or not that man or woman shall have a right to combine with others for the purpose of ... doing collectively what you can’t do individually.”

His concern proved prescient. The NLRA’s grounding in the commerce clause means that when labor disputes go to court, they are judged by their potential impact on business. The last half-century has demonstrated that, by this yardstick, the courts consistently sympathize with business interests. As a result, unions are hampered by rules that would never be applied to corporations, or to any other form of political action.

Consider what happens when workers decide to form a union. The rules of union certification elections, set by a series of unfortunate court cases and NLRB decisions, permit employers to force workers to attend “vote no” presentations or be fired.

In a 2009 study, Cornell University’s Kate Bronfenbrenner found that employers utilized these captive audience meetings in nine out of 10 union elections. Employers threatened to cut wages and benefits in 47 percent of documented cases, and to go out of business entirely in 57 percent of cases. In one in 10 instances, bosses actually hired goons to impersonate federal agents and lie about the process. Not surprisingly, unions lose 57 percent of elections when employers run these “captive audience” meetings.

Ironically, corporations have argued for—and won—the right to hold these meetings on the grounds of their First Amendment rights as “persons.” Yet union advocates possess no equivalent right to hold their own “vote yes” meetings.

The captive audience meeting is but one of many areas in which labor law favors employers. Workers form unions because they want a say on the job. Yet employer-friendly court decisions have created a distinction between “mandatory” and “permissive” bargaining issues. Employers are required to bargain over the former, but can legally tell the union to go to hell when it raises the latter. Labor law thus removes from the bargaining table many of the issues that matter most to workers, including the decision to downsize, subcontract or shift work overseas.

The existing labor law regime even circumscribes solidarity, the lifeblood of unions. “An injury to one is the concern of all” is one of the oldest precepts of the labor movement, yet it is illegal for unions and workers to officially join others’ strikes and boycotts.

Corporations, by contrast, engage in so-called secondary boycotts all the time. Cable providers, for example, black out television channels to protest a network’s rate increase, instructing viewers to call the network CEO to complain. Why are secondary boycotts legal when used by media companies for profit, but illegal when exercised in solidarity by workers?