On Tuesday, the Supreme Court decided to hear a case — Friedrichs v. California Teachers Association — that could deal a death blow to public sector unions.

Unions are required by law to bargain on behalf of every worker in their bargaining unit, regardless of whether the workers themselves are union members. ThinkProgress' Ian Millhiser rightly noted that this creates a free-rider problem, in which workers can benefit from a union's efforts without actually contributing any resources. Under such circumstances, unions would obviously have a huge problem financing themselves, and would likely fall apart. So they solve matters by charging every worker in the bargaining unit a fee, union member or no.

But a group of California teachers is arguing in Friedrichs that this arrangement violates their freedom of speech, because they're effectively financing lobbying they may not agree with.

As Milhiser explained, the argument rests on the First Amendment specifically. So if the justices find in favor of it, they could introduce all sorts of weird conundrums into how the government interacts with its workers. But the broader structure of the argument also implicates private-sector unions: They also face the same free-rider problem, so they often establish contracts with employers that require every worker covered by the bargaining unit to join the union.

"Right-to-work" laws, much beloved by conservatives and union opponents, prevent these arrangements, and thus threaten the survival of unions in the same way.

Technicalities aside, these sorts of fights over union and labor law tend to boil down to gut instincts over fairness. So there's always a certain idealism hanging in the background: a vision of a world where bosses and workers alike are perfectly free to bargain with each other as pristine, equal, homo economicus algorithms. So a lot of the discussion implicitly revolves around what that pristine, untouched "Time Zero" looked like, in order to reverse engineer society and policy from there.

In the conservative view, this Time Zero would entail an unfettered marketplace with no outside interference whatsoever. The problem is that Time Zero never existed. Humanity's modern market system was built atop previous societies and arrangements, all of which involved flaws and injustices and inequalities in power and resources that were carried over in various ways into successive systems.

This is why, practically speaking, labor fights always seem to descend into endless tit-for-tats. Union supporters point out right-to-work laws are exactly the kind of government interference conservatives claim they oppose elsewhere. And corporations use shareholders' money for lobbying efforts that, under Friedrichs' logic, violate shareholders' free speech rights in exactly the same way.

But then right-to-work supporters say these are merely efforts to counteract the unfair advantage the very existence of labor law gives to unions; so the ideal state would be no right-to-work laws and no labor laws. But then labor law limits unions, too — they have to bargain for all workers, they can't engage in sympathy strikes, etc. But unions clearly prefer the existence of labor law to its nonexistence. And around and around it goes.

There are ways to break out of this bind. If you really can't stomach unions, there are policies that can level the playing field between workers and employers in other ways. Big and generous social safety nets give workers a source of income that isn't job-dependent, which gives them a certain amount of leverage. Radical approaches to monetary stimulus could achieve much the same thing. And both options would drive the economy towards full employment to boot.

But roughly the same political coalitions that object to unions also object to these policies, usually based on the same "fairness" objections that descend into the same existential pit.

Because the government defines property and contract law and so forth, it sets the parameters by which the economy can exist at all. There is not, nor has there ever been, a perfectly "free" or "fair" or "un-interfered-with" economic state. There were simply previous setups, which distributed resources one way, and possible future setups, which distribute them another way.

If a truly "free" world must be one where workers and owners negotiate with each other as unencumbered individuals, then by necessity it must also be one where workers are as free as owners to simply walk away from the bargaining table. That, of course, is an impossibility. Society has to engage in some amount of productive activity to create anything for anyone to use in the first place. So ensuring that activity occurs requires that necessity be felt at the individual as well as the collective level.

So the question becomes, who feels the necessity, and how acutely? Or, to get much more specific in our political language, which classes feel it, and how acutely? The workers? Or management? That's the framework in which the debate over unions must be carried out, in the upcoming Friedrichs case, or in any other sphere.