(Reuters) – The U.S. Supreme Court veered from historical precedent on Wednesday in a pro-business ruling that further hampers organized labor and makes it harder for workers to unionize.

The court overturned a California regulation that had been in place since 1975, a crowning achievement of a campaign by celebrated civil rights activist Cesar Chavez. The regulation allowed union organizers to enter corporate farms after giving notice and talk with employees for three non-working hours a day, during four 30-day periods each year.

This week’s decision in the Cedar Point Nursery case is another example of the Supreme Court’s ongoing erosion of organized labor power, including a major blow in 2018, when its Janus v. American Federation of State, County and Municipal Employees ruling shut off a key source of union funding considered lawful since 1977.

Cedar Point Nursery and Fowler Packing Co filed suit after a dispute with the United Farm Workers union. According to the lawsuit, organizers disrupted work on Cedar’s property with bullhorns, while Fowler, in a complaint to state regulators, was accused of denying organizers access. The companies were backed by the Pacific Legal Foundation, a libertarian legal group that has taken on a slew of other stridently pro-business litigation.

“The access regulation grants labor organizations a right to invade the growers’ property. It therefore constitutes a per se physical taking,” Chief Justice John Roberts wrote.

Notably, the conservative majority’s argument parallels the same dangerous reasoning used by segregationists when the 1964 Civil Rights Act was being enacted. (“Anti-discrimination laws grant Black people a right to invade my restaurant. They therefore constitute a taking, and violate my right to exclude whomever I choose from my property.”).

But there’s another, more apparent issue: Under what circumstances does temporary access become equivalent to physical taking?

Justice Stephen Breyer offered some answers in his dissent, writing that “technically speaking, the majority is wrong.”

The regulation “does not take from the owners a right to invade (whatever that might mean),” Breyer wrote. “The regulation regulates (but does not appropriate) the owners’ right to exclude.” (Emphasis is Breyer’s.)

I asked Pacific Legal Foundation’s legal operations director Joshua Thompson about the majority’s interpretation of the word “taken.”

The decision is “not an expansion of what constitutes a ‘taking’; at most it is a clarification of what constitutes a physical taking,” Thompson said

On the other hand, the word “taken” doesn’t seem to need much exposition. In fact, the word “taken” in this context has been understood to mean exactly what it sounds like for over 200 years. Attorney Dayna Zolle at the Constitutional Accountability Center pointed me to a constitutional treatise from 1803 which notes that the clause “was probably intended to restrain the arbitrary and oppressive mode of obtaining supplies for the army” that was “frequently practiced during the revolutionary war.”

Precedent in this area does recognize that a “taking” can be something short of physically commandeering property. But those cases usually involve considerable interference with the fundamental ability to use one’s land – as in the endangered species example. (It’s worth pointing out that the companies simply sought an injunction against the regulation and didn’t allege damages at all. And the majority ignored the question, despite that the Constitution is clear that compensation is the remedy in these cases.)

Stanford Law School professor Bill Gould told me that the conclusion that this type of access amounts to a taking is “disingenuous, at best.” Gould was previously chairman of the California Agricultural Labor Relations Board that issued the regulation and was also chairman of the National Labor Relations Board.

“The majority derived a Constitutional principle out of whole cloth,” Gould said. “And the ruling conjures up the Supreme Court of the 1930s, which frequently invalidated social and economic legislation because it simply disagreed with lawmakers” on policy.

Defendants and amici also asserted that the ruling could encompass other governmental activity on private property, like law enforcement, or health and safety inspections. (The court said there are exceptions for those activities, without substantial explanation.)

The decision’s implications to law enforcement provide some interesting thought experiments.

Consider an argument that frequent police patrols in one’s privately owned apartment complex amount to a per se physical taking. Or that frequent police patrols in one’s neighborhood amount to a physical taking.

And, just last year, a group of homeowners and business owners filed a lawsuit against Seattle, arguing that “their property rights have been infringed upon as their vehicles must navigate the barricades” necessitated by continuous, anti-racism protesting in the Capitol Hill neighborhood, Reuters reported in an article aptly titled “Who Owns the Street?”

Under the Supreme Court’s reasoning in Cedar point, it’s reasonable to ask when the frequency of jump-outs, warrantless searches, or even regular patrols cross the line and become a “taking” of property rights.

That argument seems much less likely to fly with the court’s conservatives – but that isn’t because it diverges from their own logic.