As the British realized in 1776, nothing grabs Americans' attention quite like taxes do. I think we're in the midst of another tax rebellion, and the recent rejection of huge tax hikes by the citizens of Alabama was the most recent battle. In 2002, a ballot initiative in Massachusetts that would have eliminated all state income tax was narrowly defeated, but will be re-proposed in 2004. In July, 2003, the Nevada Supreme Court intervened to raise state taxes when the legislature refused to do so. A similar scam was tried in California, but was rejected; despite California's huge deficit, our legislature refused to raise taxes (at least the Republicans did).
There are many more such stories; many states are considering initiatives such as the one that failed in Massachusetts in 2002, and eventually one such attempt will pass. Once a single state income tax is eliminated via ballot initiative, I expect that many others will follow. The Fair Tax Act of 200X won't be far behind.