Nullification, the theory that states may invalidate federal law they declare unconstitutional, was first proposed in 1798. Since that time, attempts by state to engage in Nullification have been declared unconstitutional in 1809, 1813, 1819, 1821, 1824, 1832, 1842, 1859, 1958, and 1960. So yeah, the Supreme Court is pretty sure Nullification isn’t constitutional.
The Kansas City Star summed it up nicely with their January 20th article about Nullification:
“The states can’t simply choose to defy and override a valid federal law,” said Allen Rostron, a professor of constitutional law at the University of Missouri-Kansas City. The U.S. Constitution deems federal statutes “the supreme law of the land,” Rostron said, a fact that was tested and confirmed by the Civil War. Attempts to invoke state supremacy have been shot down over the years by generations of U.S. Supreme Court decisions. That legal view hasn’t quelled enthusiasm among conservatives. According to the National Conference of Legislatures, forms of nullification legislation have been introduced in two dozen states in recent years. In Missouri last year, the House approved legislation making it a crime for any government official in the state to enforce the Affordable Care Act, otherwise known as Obamacare. Another bill went further, attempting to amend the state’s constitution to prohibit Missouri from recognizing or enforcing any federal law. The fact that the Supreme Court refuses to recognize Nullification shouldn’t be surprising because, well, the constitution does not actually contain any clause providing that the states have the power to declare federal laws unconstitutional, like none at all.
The pesky little fact that Nullification is wholly and absolutely unconstitutional hasn’t deterred the Missouri General Assembly from, in their infinite wisdom, proposing over a dozen Nullification bills on a variety of topics. Despite the pressing economic issues in the state, the Missouri General Assembly is focusing its efforts on a legal theory that has never been upheld in any United States Supreme Court decision, ever.