The King amendment is a sort of legislative kudzu, so invasive and dangerous it could crowd out hundreds of state and local laws setting appropriate standards for agriculture. For the animal welfare movement, to put a fine point on its impact, King’s measure could very easily repeal a long list of state laws regarding shark finning, puppy mills, extreme confinement of farm animals, and the slaughter and sale of meat from horses, dogs, and cats.

To those of us who work on animal welfare, King’s radical plan is no surprise.  During his career in Congress, King has also opposed federal measures to crack down on animal fighting and horse slaughter, opposed federal animal welfare standards for hens in the egg industry, and was even against a federal policy to help pets in disasters.  So he’s long opposed federal standards for animal welfare, and now we know he opposes state standards for animals, too.

In a bipartisan show of force against the King amendment, 166 House lawmakers and 23 Senators wrote to the leadership of their chamber’s Agriculture Committee and expressed opposition to the King amendment. The letter from Democratic members, led by Reps. Kurt Schrader (D-Ore.) and Gary Peters (D-Mich.) noted that “[t]his provision threatens to undermine an untold number of duly-enacted state laws and regulations affecting agricultural production.”

The letter from House Republicans, led by Rep. John Campbell (R-Calif.) explained that the “King amendment is very broadly written to nullify state laws that impose ‘a standard or condition’ on agricultural products and to establish federal supremacy.”  They added, “[t]he federal government should play a complementary role to the states on agriculture policy, rather than rendering them powerless … ” and that the “King amendment … could jeopardize the entire Farm Bill.”

The King provision is an unprecedented assault on the historic power of states to protect health and welfare of their own citizens. It would force states to authorize “any agricultural product” regardless of safety, ethics, environmental impact or other concerns to a particular state. If any one state were to tolerate the production or sale of a particular agricultural product, no matter how offensive or threatening to the public interest, then the other 49 would be forced to do so as well. With many lawmakers conducting public events in their district, there’s no doubt they will hear from constituents urging them to reject the King amendment and to oppose the Farm Bill if it contains the King amendment or anything like it.

Pacelle is president and CEO of The Humane Society of the United States.