LET'S say you consider America's federal gun-control laws to be uniquely dangerous instruments of government oppression. You think the second amendment gives citizens the right to buy, carry, transport and sell pretty much any weapon they like. What do you do? If you’re a Kansas state legislator, you and your governor decide to enact the Second Amendment Protection Act:

Any act, law, treaty, order, rule or regulation of the government of the United States which violates the second amendment to the constitution of the United States is null, void and unenforceable in the state of Kansas.

One might wonder why the second amendment needs protecting by Kansas's politicians. The Supreme Court has been defending it robustly in recent years, with twocases giving wide scope to individual gun-ownership rights. But Kansans insist on more: exempting themselves from laws like the Gun Free School Zones Act and the Protection of Lawful Commerce in Arms Act. And there’s more: S.B. No. 102 makes it a felony for federal agents to attempt to do their job within the state of Kansas:

It is unlawful for any official, agent or employee of the government of the United States, or employee of a corporation providing services to the government of the United States to enforce or attempt to enforce any act, law, treaty, order, rule or regulation of the government of the United States regarding a firearm, a firearm accessory, or ammunition that is manufactured commercially or privately and owned in the state of Kansas and that remains within the borders of Kansas.

That’s right: it is now a crime for a federal officer to enforce federal law in Kansas.

How can the trapezoidal midwestern state do this? Well, it can’t, and Attorney-General Eric Holder has the unenviable job of explaining why. In a letter to Sam Brownback, the governor of Kansas, Mr Holder was all business:

In purporting to override federal law and to criminalise the official acts of federal officers, SB102 directly conflicts with federal law and is therefore unconstitutional. Under the Supremacy Clause…Kansas may not prevent federal employees and officials from carrying out their official responsibilities. And a state certainly may not criminalise the exercise of federal responsibilities. Because SB102 conflicts with federal firearms laws and regulations, federal law supercedes this new statute; all provisions of federal laws and their implementing regulations therefore continue to apply.

It is remarkable that a civics lesson like this is necessary. But Kansas has actually raised the stakes. Mr Brownback launched a defiant response to Mr Holder’s letter (“the people of Kansas have expressed their sovereign will”, he wrote, and the attorney-general’s perspective is merely “the view of the Obama administration”) and dozens of other states have considered similar legislation. A teachable moment presents itself.

The technical term to describe Kansas’s legislative move is “nullification”. Before the civil war, several states worried the federal government was encroaching on their sovereignty and threatening to regulate slavery against their wishes. After John Calhoun claimed the power of South Carolina to nullify a federal tariff in 1830, President Andrew Jackson was not amused. “The Constitution of the United States...forms a government, not a league”, he wrote. Rejecting a federal law will “destroy the unity of a nation.” In the tome from which this blog borrows its name, Alexis de Tocqueville put it this way: “when the majority has once spoken, it is the duty of the minority to submit.” The civil war put an end to southern nullification efforts, but the idea sprang up again when several states registered intransigent opposition to school desegregation efforts in the 1950s. The Supreme Court unanimously rebuffed legislation to undermine the Brown v Board of Education decision, reminding Arkansas that the constitution is the supreme law of the land and that the court, as per Marbury v Madison, has the final word on what the constitution means.

But legislators in Kansas insist that their interpretation of the second amendment must not be trifled with. Pointing to the guarantees of the ninth and tenth amendments, as well as the second, the Kansas law insists on defending the right to bear arms “as that right was understood at the time that Kansas was admitted to statehood in 1861, and the guaranty of that right is a matter of contract between the state and people of Kansas and the United States...” The legislation is silent on the historical matter of how the second amendment was regarded a century and a half ago; the emphasis, despite this disingenuous social-contract framing, is on how Kansans view that right in 2013. That much is clear. What is less clear is how the people of Kansas think the American story will continue to be written if all 50 states are empowered to ignore federal laws and punish federal agents who try to carry them out.