Montana vs. the Justice Department

State lawmakers have done a lot since President Obama's election to shake off Uncle Sam, passing "sovereignty" resolutions and a record number of laws that specifically defy Congress on issues such as legalized marijuana and health-care reform. Most make the same claim: that the U.S. Constitution gives the federal government power to regulate commerce between states but doesn't permit interference in purely local affairs. Later this year, the Montana Firearms Freedom Act, which proclaims that guns manufactured in Montana and sold in state are not subject to federal rules such as background checks, is slated to become the first of these Obama-era commerce challenges tested in court. But the case, which originated when a gun-rights group sued the Justice Department for threatening a crackdown, shouldn't give separatists hope: it's doomed to fail, as will similar rebukes.

That's because no state is an island (Hawaii included), and Congress can regulate anything that could jump state lines. It's a category, says George Mason University professor Nelson Lund, a Second Amendment scholar, that excludes almost nothing—certainly not pot and guns.