The case before the court involved California’s Proposition 12, which voters passed in 2018. It said that pork sold in the state needs to come from pigs whose mothers were raised with at least 24 square feet of space, with the ability to lie down and turn around. That rules out confined “gestation crates,” metal enclosures that are common in the pork industry. The Iowa-based National Pork Producers Council and the American Farm Bureau Federation sued.