WASHINGTON – The Supreme Court on Thursday rejected a challenge to a California animal welfare law that would ban the sale of pork derived from breeding pigs housed in confined spaces.

In a 5-4 ruling in which the court split along non-ideological lines, the majority said the measure, known as Proposition 12, did not illegally regulate pork produced in other states, as the challengers claimed. The law is currently on hold as part of separate litigation in state court.

The ruling authored by Judge Neil Gorsuch protects the ability of states to enact laws intended to protect the health and well-being of the public, even if the measures have an impact outside of the state. Groups supporting California had warned that a sweeping ruling against it could limit the ability of states to enact laws on a wide range of issues, including measures aimed at addressing climate change, such as efforts to reduce reliance on fossil fuels by promoting renewable energy. .

“While the Constitution addresses many important issues, the type of pork chops that California merchants are allowed to sell is not on that list,” Gorsuch said.

Californians passed Proposition 12 in 2018 with nearly 63% of the vote, a margin of more than 3 million votes. The measure would require sows to have at least 24 square feet of space in their pens, which would allow them to turn around. The state’s lawyers noted in court documents that voters were told the measure, which is no longer in effect, would most likely increase the price of pork but provide more humane living conditions for pigs and potentially reduce the risk of foodborne illness.

The National Pork Producers Council, which represents the pork industry, and the American Farm Bureau Federation, which represents agricultural interests, sued in 2019, saying the move violates a provision of the Constitution called the Commerce Clausewhich has been interpreted to prevent states from interfering with interstate commerce.

The challengers said the measure would impermissibly interfere with interstate commerce in part because nearly all pork sold in California is produced out of state by farmers who currently would not comply. The law would also place an undue burden on out-of-state entities with no clear in-state benefit, they argue. As a result, they say, the law has an illegally broad extraterritorial effect.

Lower courts upheld the move, prompting challengers to turn to the Supreme Court, which has a 6-3 conservative majority.

Other states have passed similar laws based on moral concerns, including nine that ban products tested on animals and eight that ban eggs produced by caged hens, lawyers for the Humane Society of the United States said. Nine states also ban the sale of fetal tissue from aborted fetuses, according to court documents.

Groups challenging the California law said in court documents that Proposition 12 will “transform the hog industry across the country” because nearly all farmers currently keep sows in pens that do not comply with the law.

That view was challenged by California and its allies, including meat producer Perdue Premium Meat Co., which filed a brief in the case saying its Niman Ranch brand has been raising hogs for years that would have met the requirements of the Proposition 12.

California Attorney General Rob Bonta, who is charged with upholding the law, said in court documents that the measure was valid under the commerce clause because it was not intended to benefit California growers over out-of-state competitors.

The Biden administration sided with the plaintiffs in the case, and Attorney General Elizabeth Prelogar said Proposition 12 unreasonably restricts interstate commerce in part because it regulates the welfare of animals that are not within state lines. The claimed benefits also do not justify the radical nature of the law because its health benefits have not been established, she argued.