Union activists eager for a free speech fight after the Supreme Court’s Janus v. AFSCME attack on union rights may have found one in the form of a giant inflatable rat.

Bloomberg reported last week that Trump-appointed General Counsel Peter Robb wants to issue a rule making it illegal to engage in any protest activity in the company of a balloon rat.

Cartoon rats—often with nasty red eyes, gnarly teeth and occasionally suitcases and neckties—have been a feature of worker demonstrations in the United States for almost 30 years. Initially conceived as a way to circumvent the Taft-Hartley Act’s restrictions on unions coming to the aid of fellow unions during a strike, they have since become a routine presence at legal picket lines and protest rallies. When not nicknamed “Scabby,” a rat is often named in ways that satirize an unfair boss. Many workers who find themselves in tough fights are warmed by this meme-of-memes’ way of dragging a low-road employer’s image even lower.

The rat’s legality under the Taft-Hartley Act has been heavily litigated and the symbol’s free speech protections are a mostly settled precedent. It’s not entirely clear what Robb’s legal strategy for exterminating the rat could be; what is clear, one senior NLRB official told Bloomberg, is just that he “hates” the inflatable beasts. One option reportedly under consideration would be to declare the rat’s presence at any strike, picket line, or rally to be inherently “coercive.” Conjuring up the worst union thug stereotypes, the argument would be that the presence of a large balloon implies the threat of violence and property destruction for those who do not comply with its silent demands.

It would be a curious time for the NLRB—which is tasked by statute to enforce and protect workers rights—to further restrict workers’ right to protest, and do so in a way that raises major First Amendment concerns. In June’s Janus decision, the Supreme Court endorsed an argument that any interaction that a union has with an arm of the government is inherently political, finally injecting the First Amendment directly into labor law. That was because in order to cripple public sector unions, the Court’s rightwing justices had to invent a free speech right for workers covered by union contracts who refused to pay for their representation or engage in union activity. If Scabby the Rat winds up before the Supreme Court, how would those justices reconcile their Janus affirmation of First Amendment rights to workers’ ability to freely engage in union activity?

Inflatable vermin were already a work-around for an egregious restriction of workers’ speech rights. The law currently forbids workers engaged in a union fight from talking to workers at companies that do business with their employer and asking those workers to strike their own employer in solidarity.

But the unequal application of the First Amendment to labor relations hardly ends there. Consider the legally-sanctioned “captive audience meeting.” In the run-up to an NLRB-conducted union certification election, an employer is allowed to force workers to attend mandatory anti-union presentations. In these meetings, the employer can threaten workers’ job security and benefits, as long as the threats are phrased as economic possibilities. They can even lie to workers about the process and the law, with one in ten employers going so far as to hire consultants to impersonate government agents, according to research from Cornell University.

A worker who refuses to attend a captive audience meeting can be legally fired. Pro-union workers have no right to respond or to correct the record and no right to equivalent access to address the electorate.

Consider also the Jefferson Standard doctrine that workers lose their legal organizing protections if they make “disloyal” statements about their employer. In one recent case that I highlighted previously, six employees at a Jimmy Johns franchise were fired for circulating leaflets to customers protesting their employers’ policy of forcing sick employees to report for work.

Two years ago, I authored a report for the Century Foundation calling “for unions and their allies to return to the rights-based rhetoric and constitutional legal strategies that preceded the passage of the National Labor Relations Act and the development of our current labor law regime.” Because federal labor law is constitutionally rooted in Congress’s power to regulate interstate commerce, the courts have built up a body of case law that considers unions’ impact on business first and foremost—with the constitutional rights of workers to free speech only a distant concern.

Part of what I was trying to challenge was the overly cautious strategy of union lawyers to avoid the courts—even as workers’ legal rights continue to be assaulted—for fear of unknown consequences. But what are the consequences of inaction if the rat is outlawed? That the courts might also outlaw the inflatable skunks and cockroaches that some unions have used as “just in case” alternatives? Spare us this small-bore thinking. If the NLRB tries to outlaw Scabby, they will present workers’ advocates with a strong case to make a First Amendment challenge to the Taft-Hartley Act’s unconstitutional ban on solidarity activism.

After all, is the presence of the rat outside of a non-union workplace or on a union picket line coercive? Hardly. The sad truth is that Scabby is largely ineffective at silently encouraging even the most ardent union supporter to take action. As I write this, there’s a giant rat outside the building across the street from the labor education center where I work. It’s under the (presumably) non-union scaffolding around the Cadillac dealership on Hudson Street in Manhattan’s Soho neighborhood. Nobody’s even handing out leaflets to explain the labor dispute. There’s a sign exhorting passersby to take a picture of the rat and post it on social media using the hashtag #WhyTheRat to learn more. I posted my tweet into the digital ether two weeks ago, and I still don’t know why Scabby’s hanging out in the hood.

What the rat does—and effectively—is raise the spirits of workers who know a rat when they see one. They turn union-busting employers into objects of ridicule. NLRB Counsel Robb spent his private sector legal career representing construction industry employers, who no doubt passed countless billable hours complaining to him about their pest problems. Bosses really are personally offended to be called a rat and to have giant inflatable rats mocking them outside of their property. That is what makes defending Scabby the Rat a First Amendment issue. An agent of the government is making a value judgment about the method and content of unions’ free speech and protest activity that has nothing to do with its impact on commerce or his agency’s charge under the law.

Such a case, at a minimum, may heighten the contradictions of the post-Janus legal world. If the First Amendment applies to labor relations, then it must apply to workers’ speech in their attempt to win or defend a union just as much as it does to workers’ speech when they quit one.

[This post originally appeared at The American Prospect.]