"A lot of sheriffs are now standing up and saying, 'Follow the Constitution,'" said Josephine County Sheriff Gil Gilbertson, whose territory covers the timbered mountains of southwestern Oregon.

Gun advocates have seen Obama as an enemy despite his expression of support for the interpretation of the Second Amendment as a personal right to have guns. So his call for new measures — including background checks for all gun buyers and Senate confirmation of a director of the Bureau of Alcohol, Tobacco, Firearms and Explosives — triggered new vows of defiance.

In Mississippi, Gov. Phil Bryant, a Republican, urged the Legislature to make it illegal to enforce any executive order by the president that violates the Constitution.