The Supreme Court heard arguments Tuesday over a California animal cruelty law that could raise the cost of bacon and other pork products nationwide.

The case's outcome is important to the nation's $26-billion-a-year pork industry, but the outcome could also limit states' ability to pass laws with impact outside their borders, from laws aimed at combating climate change to others intended to regulate prescription drug prices.

The case involves 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, including the ability to lie down and turn around. That rules out the confined "gestation crates," metal enclosures that are common in the pork industry.

Two industry groups, the Iowa-based National Pork Producers Council and the American Farm Bureau Federation, sued over the proposition. They say that while Californians consume 13% of the pork eaten in the United States, nearly 100% of it comes from hogs raised outside the state, primarily where the industry is concentrated in the Midwest and North Carolina. The vast majority of sows, meanwhile, aren't raised under conditions that would meet Proposition 12's standards.

The justices appeared to be split on Tuesday regarding the case, with those on either side of the political spectrum raising serious questions about wading into this ruling.

Justice Amy Coney Barrett weighed in with a hypothetical during the proceedings: "Could you have California pass a law that said we’re not going to buy any pork from companies that don’t require all their employees to be vaccinated or from corporations that don’t fund gender-affirming surgery or that sort of thing?"

On the opposite side of the spectrum, Justice Elena Kagan presented a speculative question of her own, acknowledging the country's heated partisan split: "Do we want to live in a world where we’re constantly at each others’ throats and ... Texas is at war with California and California at war with Texas?"

Kathy Hessler, an assistant dean for the Animal Legal Education Initiative at George Washington University Law School, says this case is about more than how the sausage gets made, but rather is about the U.S. Constitution's Commerce Clause, which prohibits unreasonable restrictions on the flow of products between states.

Pork producers are waiting to see if the high court will allow California to improperly regulate an industry outside its jurisdiction. 

Hessler says if the Supreme Court rules against Prop 12, the implications could be far-reaching. For example, the court's ruling could call into question California’s ability to establish its own emissions guidelines for vehicles sold in the state. 

"There are a number of questions at stake," she said, adding: "What happens if the state of California or any other state isn't allowed to make these decisions for themselves, just because it does have an impact on businesses elsewhere?"

Hessler argues that it's not "democracy" if the high court is telling people how they can conduct business, calling it a curious choice for the justices to hear this case after the court’s landmark decision earlier this year ending the constitutional right to an abortion.

There’s no federal law protecting animal welfare and that means this case will be closely watched as the court decides whether to uphold the voice of voters or the interests of the pork producers. 

Pork producers argue that 72% of farmers use individual pens for sows that don't allow them to turn around and that even farmers who house sows in larger group pens don't provide the space California would require. They also say implementing Prop 12 will cost farmers over $3,000 per sow, which they argue will make it more costly for customers amid record-high inflation.

They argue that the way the pork market works, with cuts of meat from various producers being combined before sale, it's likely all pork would have to meet California standards, regardless of where it's sold. Complying with Proposition 12 could cost the industry $290 million to $350 million, they say.

So far, lower courts have sided with California and animal-welfare groups that had supported the proposition. But for a number of reasons the law has yet to go into effect.

The Biden administration, for its part, is urging the justices to side with pork producers. The administration says Proposition 12 would be a "wholesale change in how pork is raised and marketed in this country." And it says the proposition has "thrown a giant wrench into the workings of the interstate market in pork."

California's Proposition 12 also covers other animals. It says egg-laying hens and calves being raised for veal need to be raised in conditions in which they have enough room to lie down, stand up and turn around freely. Those parts of the law aren't at issue in the case.