Texas in charge? Did the Supreme Court give red, blue states more power over national policy?

 WASHINGTON – Red states have required publishers to change the content of history textbooks to downplay race struggles and play up religious figures. And blue states have approved environmental standards that are tougher than those in other parts of the country.

Sometimes those policies and others like it spill outside a state's lines.

Now, some experts say a new Supreme Court decision upholding a California animal welfare law might make it easier for states − conservative and liberal − to impose policy choices on large swaths of the nation.

"If you're Gavin Newsom or Ron DeSantis and you're looking to project your legislation outside of your state, you probably feel more confident today than you did yesterday," said Ruth Mason, a University of Virginia School of Law professor, referencing the Democratic governor of California and the GOP governor of Florida.

Decision:Supreme Court sides with California on animal welfare law that could have impact beyond bacon

Argument:Supreme Court majority questions California law regulating pig pens, pork products

How a Supreme Court case about bacon could empower states

In California, pork must come from pigs that have larger pens than most farmers provide. The animal welfare law in question − known as Proposition 12 − requires companies selling pork in California to ensure the sow from which the butchered pig was born was housed in at least 24 square feet of floor space. While California residents consume a lot of pork, the state produces very little of it – meaning Prop 12's burden falls mostly on farmers in the Midwest and South.

The pork industry sued, claiming the Constitution bars these types of interstate policies in almost every case. A 5-4 majority of the Supreme Court balked at that interpretation Thursday. But the heavily fractured decision did little to clarify what's allowed and what isn't.

To say there's not a hard-and-fast rule, as the court did, "seems right," said Mason, an expert in federalism. "But then what is the rule? The rule can't be there is no limit on what a state can do."

Michael McConnell, director of the Constitutional Law Center at Stanford Law School and a former federal appeals court judge, said he, too, is concerned about how states will respond to the decision.

"I fear the court's opinion will open the door to any number of state-level attempts to impose their wishes on the nation as a whole," McConnell said, "even when the effects are entirely in other states."

Abortion, environment, tech: How might states respond?

States have adopted divergent policies in recent years on education, the environment, labor, health care and other issues controversial and mundane. State responses to the Supreme Court’s decision last year to overturn Roe v. Wade illustrate the point, with many conservative states banning abortion altogether and some liberal states taking steps to expand access.

Things get more complicated when those policies have an effect on interstate commerce. One of the most notable examples are environmental policies. California and other states have imposed vehicle emission standards, for instance, that have forced much of the auto industry to bend to their will.

Other policies may be less obvious: New York required internet service providers to offer reduced pricing for low-income families. California imposed its own net neutrality law on internet providers, barring them from blocking or slowing some traffic or charging for faster delivery of some content.

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"There are still some open questions about the extent to which states can issue rules like this," said Tejas Narechania, faculty director at the Berkeley Center for Law & Technology. "I think the decision here maybe points toward the states being able to do more of that. I think that'll be true in the tech space, in particular."

Kavanaugh frets about 'blueprint' for other states

In a partial dissent, Justice Brett Kavanaugh fretted that the court's decision would provide a "blueprint for other states" and usher in a "new era" in which one state attempts to "unilaterally impose its moral and policy preferences" on others.

What if a state prohibits the sale of fruit packed by noncitizens, Kavanaugh asked. What if it bars the sale of goods made by workers paid less than $20 an hour, or who work for companies that decline to pay for birth control?  

'Endless litigation.' Why some spillover may be inevitable

California approved the ballot initiative in 2018 with support from about 63% of voters. The U.S. Court of Appeals for the 9th Circuit batted away the challenge from the pork industry and the Supreme Court affirmed that decision.

Justice Neil Gorsuch, who wrote the court's opinion, didn’t respond to those concerns directly. But he wrote that in the modern “interconnected national marketplace,” many state laws have the practical effect of controlling behavior beyond that state’s borders.

Adopting the rule the pork farmers wanted would, Gorsuch wrote, “cast a shadow” over what has long been understood to be the ability of states to pass laws affecting their own residents.

 "It would invite endless litigation," Gorsuch wrote, "and inconsistent results."