The Iowa Farm Bureau Federation filed an amicus brief to the U.S. Supreme Court in support of an appeal seeking to overturn California’s Proposition 12 regulation. Prop 12 bans the sale of pork from hogs that don’t meet California’s arbitrary production standards, even if the pork was raised on farms outside of California.

The American Farm Bureau Federation (AFBF) and National Pork Producers Council (NPPC) filed the challenge with the Supreme Court, arguing the...