In their US Supreme Court case against California’s Proposition 12, the National Pork Producers Council (NPPC) and the American Farm Bureau Federation (AFBF) this week filed a brief in response to issues raised by those who want the law upheld. Proposition 12 bans the sale in California of pork not produced according to the state’s production standards; nearly all pork currently produced in the United States fails to meet California’s criteria.

NPPC and AFBF argue that the 2018 ballot initiative violates the US Constitution’s Dormant Commerce Clause by being “impermissibly extraterritorial” — that is, regulating out-of-state commerce — and failing to balance state health and safety concerns against the initiative’s negative effects on interstate commerce. The agricultural organizations contend that because California imports almost all of its pork, the practical effect of Proposition 12 is to regulate wholly out-of-state commerce. They also point out that the law’s health claim — that its requirements promote food safety — is “so patently false that California has declined to defend it.”

In their reply brief, NPPC and AFBF refuted arguments from the Humane Society of the United States, other animal-rights groups, and the state of California that Proposition 12 doesn’t affect interstate commerce, calling their assertions “wrong, showing a lack of knowledge of pigs, the industry, its markets, and federal oversight.”

Oral arguments before the Supreme Court’s nine justices will take place October 11, and a decision in the case could come before the end of the year.

The same day NPPC and AFBF filed their reply brief, the California Department of Food and Agriculture completed the Proposition 12 implementation rules, more than three years after the original statutory deadline. Earlier this year, a California superior court delayed the effective date of Proposition 12 for 180 days after final implementing regulations were issued.