The U.S. Supreme Court has refused to review a constitutional challenge against California’s livestock confinement law, which critics say unlawfully harms interstate commerce.

Veal and pork cannot be sold in California if the animals were restrained from freely moving around under a 2018 ballot initiative that was opposed in federal court by the North American Meat Institute.

A federal judge refused to enjoin the law’s implementation and the 9th U.S. Circuit Court of Appeals upheld that ruling last year.

While NAMI claimed the California statute interfered with interstate commerce, the 9th Circuit said the law plausibly doesn’t have a discriminatory effect “because it treats in-state meat producers the same as out-of-state meat producers.”

The prohibition on confinement also doesn’t act as a “price control” or affect the meat industry’s “uniform system of regulation,” the 9th Circuit said. The law has restricted “a specific method, rather than imposing a burden on producers based on their geographical origin.”

The Supreme Court has now decided against hearing arguments over the 9th Circuit’s ruling, allowing the decision to stand.

The meat industry urged the nation’s highest court to take up the case, arguing the 9th Circuit’s ruling conflicts with legal precedents set by the Supreme Court and other federal appeals courts.

In practice, the California law “usurps the regulatory authority of other states,” dictates how commerce occurs outside its borders and has a “devastating effect” on farmers whose facilities don’t comply with the regulation, according to NAMI.

The meat industry’s position was backed by 20 states, which asked the Supreme Court to review the lawsuit because the 9th Circuit’s ruling means “states are entirely free to regulate out-of-state conduct” as long as they don’t involve price controls.

“The decision below therefore not only threatens economic balkanization among states but also upends the fundamental principle of equal state sovereignty,” according to a brief from the 20 states.

California’s government urged the Supreme Court against reviewing the lawsuit, claiming the regulation of in-state conduct is not “impermissibly extraterritorial” just because it has some effects outside a state’s borders.

“If an out-of-state producer does not provide the amount of space specified in the statute to a particular calf or breeding pig, the only consequence under California law is that the meat from that animal may not be sold ‘within the state,’” according to California’s brief.

The Humane Society of the United States, an animal rights nonprofit, said the ruling isn’t worth Supreme Court review because it only pertains to a preliminary injunction and “lacks a full factual record” regarding interstate commerce impacts.

The animal rights group also argued the economic effects of California’s statute are exaggerated by the meat industry.

Some major meat producers, including NAMI members, are complying with the livestock confinement standards so there is “reason to believe that petitioner’s hyperbolic exposition regarding out-of-state impacts will founder,” the group said.