From the Washington Post:
Americans rely on cheap chicken and eggs, the products of super-sizing livestock operations while squeezing costs. Farmers pack animals into tiny, crowded and dank pens, leaving hens with scarce room to extend their wings, let alone move around. There is a balance to be struck between keeping food prices low and mitigating the miserable conditions that humans impose on livestock. California’s voters tried in 2008 to push their state closer to achieving that balance, opting to require egg growers to provide hens at least enough room to extend their wings and turn around. The rule takes effect next year.
But there was a problem: The voters didn’t appreciate that other states weren’t going to follow along, and California imports about 4 billion eggs a year. States such as Missouri and Iowa, which between them account for nearly half of California’s egg imports, haven’t imposed similar cage-size requirements, so they might enjoy a cost advantage over California producers. To right that imbalance, the Golden State’s leaders approved a law requiring all eggs sold in California to come from farms that comply with its cage-size standards, no matter where they are located.
Missouri sued last month, arguing that the Constitution gives Congress the exclusive right to regulate commerce that crosses state lines. Last week, five other states, including Iowa, joined in. Though California’s law treats all businesses — in-state and otherwise — the same, the state has to show that its effects on commerce outside the state are small relative to the local concerns it addresses. That is, rightly, a tough standard : Without strong and exclusive federal regulation of interstate commerce, states could enact all sorts of nice-sounding laws in an effort to benefit local producers.
The complaint is here: http://ago.mo.gov/newsreleases/MOvsHarris-AmendedComplaint.pdf
I mentioned this issue a while back.