The US Supreme Court upheld a California law on Thursday that requires farms to provide their livestock, particularly pigs, with enough room to move if they want to sell their products in California markets. The law, Proposition 12, was set to go into effect in September 2022, but the pork industry, led by the National Pork Producers Council (NPPC), challenged its validity.

The NPPC claimed that the law violated the dormant Commerce Clause of the US Constitution. The Commerce Clause gives Congress the ability to regulate interstate commercial activity, and the dormant Commerce Clause is a doctrine courts use to strike down laws that discriminate against out-of-state commerce or place too large a burden on interstate markets. The NPPC claimed that California’s law violated this doctrine because the vast majority of the farms impacted by the law are not based in California. In a statement, the NPPC condemned the ruling for “allowing state overreach” that “will increase prices for consumers and drive small farms out of business.”

In its ruling upholding the law, the court determined that Proposition 12 did not violate the dormant Commerce Clause, although different justices came to that conclusion for different reasons. Overall, the court declined to dramatically change dormant Commerce Clause doctrine. Instead, the court focused on the fact that there was no intentional protectionism and the difficulty of measuring the benefits and burdens of Proposition 12.

Because it was not clear that the burdens on interstate commerce outweighed the benefits for California, the court determined that the dormant Commerce Clause does not prohibit this sort of regulation. Justice Neil Gorsuch summed this up at the beginning of the majority opinion, saying:

Companies that choose to sell products in various States must normally comply with the laws of those various States. Assuredly, under this Court’s dormant Commerce Clause decisions, no State may use its laws to discriminate purposefully against out-of-state economic interests. But the pork producers do not suggest that California’s law offends this principle. Instead, they invite us to fashion two new and more aggressive constitutional restrictions on the ability of States to regulate goods sold within their borders. We decline that invitation.

Proposition 12 passed in 2018, when 63 percent of California voters voted in its favor. Animal welfare organizations, like the American Society for the Prevention of Cruelty to Animals (ASPCA), previously expressed support for the law, calling NPPC’s lawsuit a “last-ditch effort” to stop reforms of a “broken system.”