In the middle of last week, Dixon O’Brien, a 60-year-old engineer, and his union, the International Union of Operating Engineers Local 150, quietly filed a federal lawsuit against Lincolnshire, a village in a northern suburb of Chicago. Together they raised issue with Lincolnshire officials using taxpayer dollars to fund a statewide lobbying group, the Illinois Municipal League, which advocates for things like limiting collective bargaining and reducing pension benefits. “O’Brien objects to the use of his tax money to fund private organizations that lobby and/or engage in other political activities that run directly against his economic interests and his political beliefs,” the complaint reads.

On Thursday, the head of the same union filed a federal lawsuit against Illinois Gov. Bruce Rauner, challenging portions of state law that requires unions to provide representational services to non-dues paying members. “It is absurd that state law forces unions to provide equal representation and service to public sector workers who are not members and pay nothing toward associated costs,” said union President James Sweeney in a statement.

And then on Friday, the International Union of Operating Engineers Locals 139 and 420 filed a federal lawsuit against Wisconsin Gov. Scott Walker, challenging a law he signed in 2011 that dramatically restricts public employee collective bargaining rights. The unions argue that the law’s restrictions impinge upon their protected free speech rights under the First Amendment.

These three consecutive lawsuits are a warning to the Supreme Court that if it buys into an extreme conservative argument being used to undermine labor unions, the justices are going to take a lot more than just agency fees down with them.

On Monday, the Supreme Court will hear oral arguments in Janus v. AFSCME, Council 31 – a case experts have long predicted could strike a mortal blow to public sector unions. The plaintiff, an Illinois state worker named Mark Janus, has argued that he has a First Amendment right to avoid paying anything to a union that bargains on his behalf. With the current ideological leanings of the court, the plaintiff — and the conservative groups backing his lawsuit — face strong odds of victory.

But while most of the media has focused on the fact that the Janus case stands to decimate union coffers – and by extension, Democratic Party coffers – some labor activists and legal scholars have begun sounding the alarm on what they say would be the unintended consequences of the suit, effectively opening up the floodgates for countless lawsuits like the recent ones filed by the International Union of Operating Engineers. If Janus doesn’t have to pay his agency fees because collective bargaining is speech he disagrees with, then collective bargaining is speech. And it can’t be restricted. Indeed, when some of Janus’s lazier advocates lay out the case, they accidentally argue on behalf of unions’ right to free speech. “Because government is both employer and policymaker, collect­ive bargaining by the union is inherently political advocacy and indistinguishable from lobbying,” wrote George Will on Sunday, directly implicating the First Amendment.

For more than 40 years, the Supreme Court has held that there’s a constitutional difference between a union’s political activities and its collective bargaining work. Compelling workers to fund the former would infringe on their freedom of speech, the court ruled in 1977. But under current law, collective bargaining is different. Imposing conditions, such as requiring mandatory dues or limiting the scope of their negotiations to wages and benefits, is fair game.

If the Janus plaintiffs win their case, this critical distinction would be dismantled. (A decision is expected by June, when the court’s term ends.) A union’s bargaining and political lobbying would be treated the same — as protected free speech. In other words, the court would actually be elevating the free speech standards of bargaining. That, in turn, could bring with it new legal protections.