BOISE, Idaho – Republican lawmakers in nearly a dozen states are reaching into the dusty annals of American history to fight President Obama's health care overhaul.

They are introducing measures that hinge on "nullification," Thomas Jefferson's late 18th-century doctrine that purported to give states the ultimate say in constitutional matters.

GOP lawmakers introduced such a measure Wednesday in the Idaho House, and Alabama, Kansas, Maine, Missouri, Montana, Oregon, Nebraska, Texas and Wyoming are also talking about the idea.

The efforts are completely unconstitutional in the eyes of most legal scholars because the U.S. Constitution deems federal laws "the supreme law of the land." The Idaho attorney general has weighed in as well, branding nullification unconstitutional....